Abstract:
A musical tone generating apparatus includes a position information generating device to generate musical instrument position information (PS) as plane coordinates  coordinate values. This information (PS) is stored in a memory device, or selectively determined by a manual operation. The apparatus also includes an information converting device to converter information (PS) into musical tone parameter control information (PD). This control information (PD) controls musical tone source signals (S 11,  S 12,  and S 13 ) to generate a sound field corresponding to the position of musical instruments arranged on a stage. This enables an operator to verify the musical instrument positions on a stage, thereby providing a feeling of being at a live performance.

Description:
This reissue application is a continuation of reissue application Ser. No.  08 / 345 , 531 , filed on Nov.  28 ,  1994 , now abandoned, which is a continuation of reissue application Ser. No.  08 / 084 , 812 , filed on Jun.  29 ,  1993 , now abandoned, which is a reissue application of U.S. Pat. No.  5 , 027 , 689  granted Jul.  2 ,  1991 . 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a musical tone generating apparatus desirable for an electronic musical instrument, an automatic musical performance apparatus, or the like, more particularly to a technique to reproduce a sound field corresponding to positions of musical instruments which are arranged on a stage of concert hall, jazz club house, or the like. 
     2. Prior Art 
     In a conventional sound effect technique, sound effect control information is preset in an apparatus so that the sound effect (e.g. reverberative effect) is desirably presented to a concert hall, jazz club house, or the like. Then, assuming that a sound effect for a specific concert hall is selected by an operator, or automatically selected, a specific sound effect is supplied of that concert hall based on the sound effect control information, by which this specific sound effect is converted to a musical tone signal. 
     Such conventional technique can present to some extent a desirable sound effect for listening to a performance, however, a sound field cannot be produced corresponding to respective positions of the musical instruments which are arranged on the stage of the concert hall, that is, the conventional technique cannot present a feeling of being at a live performance. In other words, the feeling given by the conventional technique is different from the feelings related to an actual sound field (related to a position of the sound image, a frequency component of the musical tone, a magnitude of the sound effect, or the like) since many types of the musical instruments are arranged at various positions on the stage of the concert hall, in case of a live performance. Accordingly, the conventional apparatus cannot present an accurate feeling of the sound field. 
     On the other hand, it is well known that an electronic musical instrument can have several speakers to reproduce a performance with the position of the sound image and sound effect varied by the adjustment of volume controls, switches, or the like, in which these volume controls and switches are mounted on a panel of the apparatus. 
     However, this is very complicated in that many select elements such as the volume controls and switches must be adjusted to reproduce a desirable feeling of the sound field, especially it is not easy to adjust a sound field based on an imagination of the position of the musical instruments as if these musical instruments are arranged on the stage of the concert hall. Up until recently, the sound effect control information has been thus preset in the apparatus to reproduce the sound effect corresponding to a stage of the concert hall, requiring a great deal of the information to be preset in the apparatus, and an apparatus of highly complicated construction. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is therefore to provide a musical tone generating apparatus which can reproduce sound fields by a simple operation corresponding to musical instruments as if these musical instruments are arranged on a stage of a concert hall, or the like, so as to obtain the feeling of being at a live performance. 
     Another object of the present invention is to provide a musical tone generating apparatus which can readily verify each position of the musical instruments as if these musical instruments are arranged on a stage. 
     Another object of the present invention is to provide a musical tone generating apparatus which can provide a simple operation to reproduce the sound fields of musical instruments on respective stages. 
     In a first aspect of the invention, there is provided a musical tone generating apparatus comprising: a position information generating apparatus for generating musical instrument position information corresponding to positions of the musical instruments arranged on a stage of a performance place; an information converting apparatus for converting the musical instrument position information into musical tone parameter control information; a sound source apparatus for generating a musical tone source signal having a tone color corresponding to each of the musical instruments arranged on the stage; a musical tone control apparatus for controllably generating musical tone output signals corresponding to the musical tone parameter control information relative to the position of the musical instruments by receiving the musical tone source signal from the sound source apparatus; and an output apparatus for generating a musical tone from a plurality of output channels by receiving the musical tone output signal from the musical tone control apparatus so that a sound field is reproduced corresponding to the position of the musical instruments arranged on the stage. 
     The operator can set the position information of the musical instruments in the position information generating apparatus, even the apparent position of the musical instruments can be moved to the desired position. 
     The musical tone signal output can be read from a storage apparatus, or read from musical instruments. 
     In a second aspect of the invention, there is provided a musical tone generating apparatus comprising: a select apparatus for selecting a stage from among performance places; a storage apparatus for storing musical instrument position information which indicates a position of musical instruments arranged on a stage, and tone color indication information for indicating a tone color corresponding to each of the musical instruments; a reading apparatus for reading the musical instrument position information and the tone color indication information from the storage apparatus, in which both the musical instrument position information and the tone color indicated information are selected by the select apparatus; an information converting apparatus for converting the musical instrument position information into a musical tone parameter control information corresponding to a value of the plane coordinates and a variable which is determined by the value of the plane coordinates; a sound source apparatus for generating a musical tone source signal having a tone color corresponding to each of the musical instruments arranged on the stage; a musical tone control apparatus for controllably generating musical tone output signals in response to the musical tone parameter control information relative to the position of the musical instruments by receiving the musical tone source signal from the sound source apparatus; and an output apparatus for generating musical tone from a plurality of output channels by receiving the musical tone output signal from the musical tone control apparatus so that a sound field is reproduced corresponding to the position of the musical instruments arranged on the stage. 
     The musical instrument position information can be in the form of preset information corresponding to a predetermined stage as well as tone color indication information. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing the construction of a musical tone generating apparatus of an embodiment; 
     FIG. 2 is a plan view showing the lay-out of select switches; 
     FIG. 3 is a plan view showing the lay-out of musical instruments arranged on a stage; 
     FIG. 4 is a diagram showing the control data lay-out of a memory; 
     FIG.  5 (A) to FIG.  5 (D) are diagrams showing the information memorized in ROM  18 ; 
     FIG. 6 is a diagram showing parameter control circuit 
     FIG. 7 is a diagram showing reverberative circuit  64 ; 
     FIG. 8 is a flow chart showing a main routine of the musical tone generating apparatus; 
     FIG. 9 is a flow chart showing a subroutine of stage select switch HSS; 
     FIG. 10 is a flow chart showing a subroutine for initializing sound images; 
     FIG. 11 is a flow chart showing a subroutine for detecting a movement of sound images; and 
     FIG. 12 is a flow chart showing a subroutine for setting a feature of the information. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, an embodiment of the present invention is described by reference to the drawings. 
     FIG. 1 shows a circuit diagram of an electronic musical instrument in accordance with an embodiment, in which the electronic musical instrument is controlled by a microcomputer to generate a musical tone. 
     In FIG. 1, major components are connected to bus  10 . These components are composed of keyboard circuit  12 , a group of select elements  14 , CPU (central processing unit)  16 , ROM (read only memory)  18 , RAM (random access memory)  20 , a group of registers  22 , floppy disk unit  24 , display panel interface  26 , touch panel interface  28 , sound source interface  30 , and externally input interface  32 . 
     Keyboard circuit  12  detects keyboard information corresponding to respective keys of the keyboards which are composed of an upper keyboard, a lower keyboard, and a pedal keyboard. 
     The group of select elements  14  comprises select elements for controlling a musical tone and for controlling a performance, and for controlling other functions, in which each select element detects the keyboard information. These select elements are described later by reference to FIG.  2 . 
     CPU  16  executes many types of control processes to generate a musical tone in accordance with a control program stored in ROM  18 . ROM  18  also stores musical tone parameter control information which is described later by reference to FIG.  5 . The control processes are described later by reference to FIG. 8 to FIG.  12 . 
     RAM  20  stores display control data which is read from floppy disk unit  24 . This display control data is used for a certain stage. 
     The group of registers  22  is used for the control processes when CPU  16  executes the control program. 
     Floppy disk unit  24  is used for reading and writing the display control data from and to a floppy disk which stores many different types of display control data for use in a plurality of performance place. The details of the above are described later by reference to FIG.  4 . 
     Display panel interface  26  and touch panel interface  28  are connected to display panel  34 A and touch panel  34 B, respectively, in which both display panel  34 A and touch panel  34 B are incorporated in musical instrument position setting device  34 . Accordingly, display panel interface  26  transfers display data DS to display panel  34 A, and touch panel interface  28  receives musical instrument position data PS from touch panel  34 B corresponding to the touch position of the keyboard which is detected by touch panel  34 B. Musical instrument position setting device  34  is described later by reference to FIG.  3 . 
     Sound source interface  30  transfers sound source control information TS to distributing circuit  36 , in which sound source control information TS is composed of key-on and key-off signals corresponding to the operation of the keyboard; performance information such as key-data (tone pitch data) corresponding to a depressed key; musical tone parameter control information PD read from ROM  18 ; and tone color indicated data TS and reverberation control data RVD both read from RAM  20 . 
     Externally input interface  32  receives performance information corresponding to the operation of the keyboard, and performance information read from a memory device incorporated in the electronic musical instrument. This input performance information is supplied to distributing circuit  36  through sound source interface  30 , together with a performance information from keyboard circuit  12 . 
     Distributing circuit  36  generates first sound source control information S 1 , second sound source control information S 2 , and third sound source control information S 3  depending on the type of the musical instruments indicated by sound source control information TS. The first, second, and third sound source control information S 1 , S 2 , and S 3  is supplied to first sound source control circuit (TG 1 )  38 , second sound source control circuit (TG 2 )  40 , and third sound source control circuit (TG 3 )  42 , respectively. In the addition, distributing circuit  36  receives musical tone parameter control information PD and reverberation control data RVD, both also being contained in sound source control information TS, and this musical tone parameter control information PD and reverberation control data RVD is directly supplied to parameter control circuit  44 . 
     In the sound source control information described in the above, first sound source control information S 1  represents tone color indication data corresponding to musical instrument  1  (e.g. piano) and performance information based on the upper keyboard in operation, second sound source control information S 2  represents other tone color indication data corresponding to musical instrument  2  (e.g. violin) and performance information based on the lower keyboard, and third sound source control information S 3  represents other tone color indication data corresponding to musical instrument  3  (e.g. bass) and a performance information based on the pedal keyboard. 
     In the above description, other performance information can be supplied from an electronic musical instrument through externally input interface  32 , sound source interface  30 , and distributing circuit  36 , instead of the performance information input from keyboard circuit  12 , based on the upper keyboard, lower keyboard, and pedal keyboard, so that various types of electronic musical instruments can be used to play an ensemble, which can even be an automatic performance ensemble. 
     First sound source control circuit TG 1  therefore supplies digital musical tone signals S 11  to parameter control circuit  44  corresponding to first sound source control information S 1 , second sound source control circuit TG 2  supplies digital musical tone signal S 12  to parameter control circuit  44  corresponding to second sound source control information S 2 , and similarly, third sound source control circuit TG 3  supplies digital musical tone signal S 13  to parameter control circuit  44  corresponding to third sound source control information S 3 . 
     Parameter control circuit  44  thus controls digital musical tone signals S 11 , S 12 , and S 13  based on musical tone parameter control information PD, and generates a reverberative effect signal based on reverberation control data RVD. Parameter control circuit  44  then converts such digital musical tone signals S 11 , S 12 , and S 13  into analog musical tone signals AS(R) for the right channel, and AS(L) for the left channel by a digital-analog converter incorporated in parameter control circuit  44 . The details of parameter control circuit  44  are described later by reference to FIG.  6  and FIG.  7 . 
     Musical tone signal AS(R) and musical tone signal AS(L) are supplied to right speaker  48 R and left speaker  48 L through amplifier  46 R and amplifier  46 L to generate musical tone, respectively. 
     FIG. 2 shows a lay-out of the select elements, each of which is related to this embodiment, and each of which is arranged in the group of select elements  14 . 
     In FIG. 2, performance mode switch PMS is used for indicating a normal performance mode, that is, a manual performance (or an automatic performance) can be carried out without reproducing the sound field of the selected concert hall when it is depressed. After depression, light-emitting element PML is turned on, in which this light-emitting element PML is mounted beside performance mode switch PMS. 
     Hall select switch HSS comprises N switches, which are laterally arranged in the panel. Adjacent to the N switches are respective light-emitting elements HSL. Accordingly, when one of the hall select switches HSS is depressed to select a particular concert hall. A corresponding light-emitting element HSL is turned on. The manual performance (or the automatic performance) is then carried out with reproduction of a sound field for the concert hall which is selected by the hall select switch HSS. 
     On the other hand, when the previously depressed hall select switch HSS corresponding to the turned on light-emitting element HSL is again depressed the light-emitting element HSL is turned off, and light-emitting element PML is also turned off to terminate the manual performance. 
     FIG. 3 shows a plan view of musical instrument position setting device  34  which comprises a transparent touch panel  34 B having matrix-arranged switches, and display panel  34 A arranged behind touch panel  34 B. 
     Display panel  34 A, for example, has a hall symbol HSY corresponding to a stage of performance place such as a concert hall, hall name HNM such as “HALL 1 ”, musical instrument display frame FLM, musical instrument symbol ISY, and musical instrument name INM. Musical instrument display frame FLM is displayed in touch panel  34 B having a rectangular shape, and musical instrument symbol ISY and musical instrument name INM are displayed in each musical instrument display frame FLM. In FIG. 3, hall name HNM is displayed at the left-top corner of display panel  34 A as “HALL 1 ”, musical instrument symbol ISY is displayed at the bottom-left of the display panel as “Pp” for a piano and musical instrument name INM is displayed in musical instrument display frame FLM as “piano”. Similarly, a symbol “Pv” is displayed at the bottom-middle of the display panel as “violin” which is also displayed in the musical instrument display frame, and a symbol “Pb” is displayed at the top-right of the display panel as “bass” which is also displayed in the musical instrument display frame. 
     Touch panel  34 B has rectangular coordinates which are represented by a character W corresponding to the width of the stage of a concert hall, and by a character H corresponding to the depth thereof. The origin of the coordinates (P 0 (0,0) is set at the top-left corner of touch panel  34 B, the y axis is set in a vertical direction and the x axis is set in a horizontal direction. Accordingly, the position of the piano is indicated by P p (x 1 , y 1 ), similarly, the position of the violin is indicated by P v (x 2 , y 2 ), and the position of the bass is indicated by P b (x 3 , y 3 ). 
     After roughly inputting the position of all musical instruments in display panel  34 A, the positions can be adjusted by touching a finger within musical instrument display frame FLM in touch panel  34 B corresponding to, for example, the piano position, and moving the finger to a desired position to set the piano in position. At this time, musical instrument display frame FLM, musical instrument name INM, and musical instrument symbol ISY move with the movement of the finger contact point. When the finger stops moving, the display position of the piano is finally set in touch panel  34 B. Similarly, the position of the violin and bass can also be set in touch panel  34 B in the same manner as described above. Thus, the position of the musical instruments can be selectively and readily arranged as if on the stage of a concert hall by touching and moving the finger over the surface of the touch panel  34 B. 
     FIG. 4 shows a format of display control data stored in a floppy disk. The display control data is composed of hall index data and hall data. Hall index data is composed of hall  1  (e.g. a small concert hall), hall  2  (e.g. a large concert hall), hall  3  (e.g. an outdoor stage), and hall N (e.g. a jazz club house). Hall data is composed of hall characteristic data and musical instrument data. This hall data is described later. 
     For example, when hall  1  is selected by one of the hall select switches HSS, floppy disk unit  24  reads the display control data from the floppy disk, and then writes it into RAM  20  with the format shown in FIG.  4 . 
     The hall data has identification data ID followed by hall characteristic data and musical instrument data. This hall data is used for hall  1 . The hall characteristic data is composed of a value of bytes K 0  occupied by hall name data HNMD, a value of bytes L 0  occupied by hall symbol data HSYD, a value of bytes M 0  occupied by reverberation control data RVD, as well as actual hall name data HNMD indicated by a hall name, actual hall symbol data HSYD indicated by a hall symbol, and actual reverberation control data RVD which controls the reverberative effect. A term of HAD 0  represents a head address of RAM  20  when the hall characteristic data is written into RAM  20 . Corresponding to the head address HAD 0 , hall name data HNMD, hall symbol data HSYD, and reverberation control data RVD are read from RAM  20  depending on the respective value of bytes occupied by the respective HNMD, HSYD, and RVD. 
     Musical instrument data is composed of data of musical instrument  1  (e.g. a piano), data of musical instrument  2  (e.g. a violin), and data of musical instrument  3  (e.g. a bass). 
     Data of musical instrument  1  is composed of data which indicates a value of bytes K 1  occupied by musical instrument data INMD, data which indicates a value of bytes L 1  occupied by musical instrument symbol data ISYD, and data which indicates a value of bytes M 1  occupied by tone color indicated data TSD, as well as actual musical instrument name data INMD, actual musical instrument symbol data ISYD, actual tone color indicated data which indicates a tone color (e.g. the tone color of the piano) of the musical instrument, and data which indicates the musical instrument position in the x direction (x 1 ), and data which indicates the musical instrument position in the y direction (y 1 ). A term of HAD 1  represents a head address of RAM  20  when the data of musical instrument  1  is written into RAM  20 . Corresponding to the head address HAD 1 , musical instrument name data INMD, musical instrument symbol data ISYD, and tone color indication data TSD are read from RAM  20  depending on the respective number of bytes occupied by the respective INMD, ISYD, and TSD data; and musical instrument position data PS (x 1 , y 1 ) is read from RAM  20 , in which X axis component x 1  is stored in storage area X 1 , and Y axis component y 1  is stored in storage area Y 1 . 
     While data of musical instruments  2  and  3  are handled similarly to data of musical instrument  1  described in the above, therefore details are omitted for the sake of simplicity. 
     With the terms HAD 2  and HAD 3  representing head addresses data of musical instruments  2  and  3  is read from RAM  20 , as well as musical instrument position data (x 2 , y 2 ) and (x 3 , y 3 ) indicates the position of musical instruments  2  and  3 , respectively. This musical instrument position data (x 2 , y 2 ) and (x 3 , y 3 ) is not shown in FIG. 4, but X axis components x 2  and x 3  are stored in storage area X 2  and X 3 , and Y axis components Y 2  and y 3  are stored in storage area Y 2  and Y 3 , respectively. These (x 2 , y 2 ) and (x 3 , y 3 ) components indicate musical instrument position data read from RAM  20 , but not musical instrument position data PS transferred from musical instrument position setting device  34 . 
     FIG.  5 (A) to FIG.  5 (D) show five types of musical tone parameter control information PD stored in respective memory portions of ROM  18 . 
     One of the memory stores information as shown in FIG.  5 (A). This information is composed of a normalized value P y  which indicates the value of the y coordinate of a musical instrument on the stage of the hall, and a first multiplication constant MP 1  which determines the position of a sound image in a y direction of the stage. The first multiplication constant MP 1  is directly proportional to the normalized value P y . Thus, when P y =1 and MP 1 =1, a sound image is produced corresponding to a musical instrument positioned at the most front side of the stage. 
     Another memory stores information as shown in FIG.  5 (B). This information is composed of the normalized value P y  which indicates the value of the y coordinate of a musical instrument on the stage of the hall, and a fourth multiplication constant MP 4  which determines the magnitude of a reverberative effect in the y direction of the stage. The fourth multiplication constant MP 4  is inversely proportional to the normalized value P y . Thus, when P y =0 and MP 4 =1, a reverberative effect can be produced corresponding to a musical instrument positioned at the most rear side of the stage. 
     Another memory stores information as shown in FIG.  5 (C). This information is composed of a normalized value P y  which indicates the value of the y coordinate of a musical instrument, and a filtering constant CF which determines a cut-off frequency of a low-pass filter. The filtering constant CF is directly proportional to the normalized value P y . When P y =1 and CF=f s /2 (f s  is a sampling frequency for digital musical tone signals), a sound barrier spreads to a high tone corresponding to a musical instrument positioned at the most front side of the stage. 
     Another memory stores information as shown in FIG.  5 (D). This information is composed of a normalized value P x  which indicates the value of the x coordinate of a musical instrument, and second and third multiplication constants MP 2  and MP 3  which determine the position of a sound image in the direction to the right and left of the stage. The multiplication constant MP 2  is directly proportional to the normalized value P x  as shown by “L 2 ”, while the multiplication constant MP 3  is inversely proportional to the normalized value P x  as shown by “L 3 ”. Thus, when P x =1, MP 2 =1, and MP 3 =0, a sound image is produced corresponding to a musical instrument which is positioned at the right most side of the stage. When P x =0, MP 2 =0, and MP 3 =1, a sound image is produced corresponding to a musical instrument which is positioned at the left most side of the stage. 
     On the other hand, with the normalized value P y  indicated by the position of a musical instrument along the y coordinate, and the normalized value P x  indicated by the position of a musical instrument along the x coordinate, both of the values P y  and P x  are determined from the musical instrument position data (e.g. indicated by x 1  and y 1 ) read from RAM  20 , and musical instrument position data PS transferred from musical instrument position setting device  34 . 
     FIG. 6 shows parameter control circuit  4 . This parameter control circuit  44  comprises three parameter controllers CN 1 , CN 2 , and CN 3 . These parameter controllers CN 1 , CN 2 , and CN 3  receive digital musical tone signals S 11 , S 12 , and S 13  from first sound source control circuit TG 1 , second sound source control circuit TG 2 , and third sound source control circuit TG 3 , respectively. Since parameter controllers CN 1 , CN 2 , and CN 3  are identical in construction, only parameter controller CN 1  is described in this embodiment. 
     Digital musical tone signal S 11  is supplied to multiplier  50  to be multiplied by first multiplication constant MP 1 . A multiplication value output from multiplier  50  is supplied to low-pass filter  52  to control a frequency corresponding to filtering constant CF. 
     A value output from low-pass filter  52  is supplied to multiplier  54  to be multiplied by second multiplication constant MP 2 , then supplied to multiplier  56  to be multiplied by third multiplication constant MP 3 , and also supplied to multiplier  58  to be multiplied by fourth multiplication constant MP 4 . 
     Multiplied values output from multipliers  54  and  56  are supplied to adders  60  and  62 , respectively, while a multiplied value output from multiplier  58  is supplied to reverberation circuit  64 . 
     FIG. 7 shows reverberation circuit  64 . Input data IN is supplied to adder ADD, and data output from adder ADD is supplied to delay circuit DL. Data output from delay circuit DL is supplied to multiplier MPL, and then data output from multiplier MPL is supplied to adder ADD as a feedback. Delay control data RVD 1  which is a part of reverberation control data RVD is supplied to delay circuit DL to set a delay time, and multiplication constant data RVD 2  is supplied to multiplier MPL to be multiplied by the data output from delay circuit DL, so that output data OUT is output from delay circuit DL with a reverberative effect assigned. 
     Output data OUT is supplied to both adders  60  and  62  to be added to the data output from multipliers  54  and  56 , respectively. 
     Data output from adder  60  is digital musical tone signal SR 1  for the right channel, which is supplied to adder  66 . While data output from adder  62  is digital musical tone signal SL 1  for the left channel, which is supplied to adder  70 . 
     Digital musical tone signals SR 2  and SR 3  for the right channel are also supplied from parameter controllers CN 2  and CN 3  to adder  66  to add digital musical tone signal SR 1 . In addition, digital musical tone signals SL 2  and SL 3  for the left channel are supplied from parameter controllers CN 2  and CN 3  to adder  70  to add to digital musical tone signal SL 1 . 
     Added data output from adder  66  is converted into analog musical tone signal AS(R) for the right channel by D-A converter  68  to output to a speaker. Added data output from adder  70  is also converted into analog musical tone signal AS(L) for the left channel by D-A converter  72  to output to a speaker. 
     According to FIG. 6, in multiplier  50 , the sound image can be moved in the y direction of the stage shown in FIG. 3, when first multiplication constant MP 1  is changed with respect to normalized value P y  which indicates the y coordinate of the musical instrument as shown in FIG.  5 (A). 
     In low-pass filter  52 , the fine variation of tone color can be produced corresponding to the position of the musical instrument in the y direction of the stage, when filtering constant CF is changed with respect to normalized value P y  which indicates the y coordinate of the musical instrument as shown in FIG.  5 (C). 
     In multipliers  54  and  56 , a sound image can be moved in the x direction of the stage as shown in FIG. 3, when second and third multiplication constants MP 2  and MP 3  are changed with respect to normalized value P x  which indicates the x coordinate of the musical instrument as shown in FIG.  5 (D). 
     In multiplier  58 , the magnitude of reverberative effect can be adjusted in the y direction of the stage, when fourth multiplication constant MP 4  is changed with respect to normalized value P y  which indicates the y coordinate of the musical instrument as shown in FIG.  5 (B). 
     In this embodiment, adders  60 ,  62 ,  66 , and  70  electrically mix inputs with adjusted musical tone signals, and output musical tone signals to two speakers. However, several musical tones can be mixed in the air space by using several speakers, and in this case the number of adders can be reduced. 
     The group of registers  22  is described next for use in this embodiment. 
     (1) Mode register MOD: this register stores from “0” to “2”, “0” for a normal performance mode, “1” for a musical instrument position setting mode, and “2” for a performance mode having a reproduction of a sound field (referred to as a reproduction performance mode in the following). 
     (2) Switch number register SNO: this register stores a switch number (1 to N) of hall select switch HSS when hall select switch HSS is turned on. 
     (3) Switch flags SFL 1  to SFL n : these registers set “1” to a flag corresponding to a hall select switch HSS (1 to N) when hall select switch HSS is turned on. 
     (4) Head address registers ADR 0  to ADR 3 : these registers are for storing head addresses HAD 0  to HAD 3  shown in FIG.  4 . 
     (5) x coordinate register P x : this register is for storing the normalized value P x  which indicates the x coordinate. 
     (6) y coordinate register P y : this register is for storing the normalized value P y  which indicates the y coordinate. 
     (7) Control variable register i: this register is for storing a control variable i. 
     FIG. 8 shows the flow chart of a main routine which is started by turning on a power switch. 
     In step  80 , an initialize routine is executed to initialize each register. 
     In step  82 , a “0” is set in mode register MOD for the normal performance mode. This makes light-emitting element PML turn on. 
     In step  84 , the process decides whether mode register MOD is “0” or “2” (the performance mode). When this decision is “Y”, the process moves to step  86 , otherwise it moves to step  94 . 
     In step  86 , the process decides whether keyboard circuit  12  has a key-on event of the keyboard or not. When this decision is “Y”, the process moves to step  88 , other wise it moves to step  90 . 
     In step  88 , the process executes a tone generation. This is, key-on signal and key data corresponding to a depressed key are supplied to keyboard circuit  12  to generate a musical tone, then the process moves to step  90 . 
     In step  90 , the process decides whether keyboard circuit  12  has a key-off event of the keyboard or not. When this decision is “Y”, the process moves to step  92 , otherwise it moves to step  94 . 
     In step  92 , the process executes a reduction of sound, that is, the key-off signal and the key data for a released key are supplied to the sound source corresponding to the keyboard which made the key-off event to start reduction of the musical tone corresponding to the released key, then the process moves to step  94 . 
     In step  94 , the process decides whether hall select switch HSS has an on-event or not. When this decision is “Y”, the process moves to step  96 , otherwise it moves to step  98 . 
     In step  96 , a subroutine is executed for the ON-state of hall select switch HSS, then the process moves to step  98 . Details of this subroutine are described later by reference to FIG.  9 . 
     In step  98 , another process is executed such as a setting process of a tone color, tone volume, and the like, then the process moves back to step  84  to repeat the processes. 
     FIG. 9 shows the flow chart of a subroutine when one of the hall select switches HSS is turned on. 
     In step  100 , a number n of hall select switch HSS is set in switch number register SNO when one of hall select switch HSS is turned on, then the process moves to step  102 . 
     In step  102 , the process decides whether mode register MOD is “2” (reproducing performance mode) or not. When this decision is “Y”, the process moves to step  104 , otherwise it moves to step  108 . 
     In step  104 , the process decides whether switch flag SFL n  is “1” (the sound field for reproduction for a stage corresponding to a value n set in switch number register SNO) or not. When this decision is “Y”, the process moves to step  106 , otherwise it moves to step  108 . 
     In step  106 , a “0” is set in mode register MOD, and the light-emitting element PML is turned on. A “0” is set in respective switch flags SFL 1  to SFL n  to turn light-emitting element HSL. Afterwards, the process returns to the main routine shown in FIG.  8 . In this case, the hall select switch HSS corresponding to a value is turned on, to reproduce a sound field corresponding to a value n, and the reproduction mode is canceled to return to the normal performance mode. 
     In step  108 , a “1” is set in mode register MOD, and light-emitting element PML is turned off, then the process moves to step  110 , and is changed from the normal performance mode to the musical instrument position setting mode when the process has come from step  102 , and is changed from the reproducing performance mode to the musical instrument position setting mode when the process has come from step  104 . 
     In step  110 , a “1” is set in switch flag SFL n  to turn light-emitting element HSL on. A “0” is also set in switch flags SFL except for switch flag SFL n  to turn respective light-emitting elements HSL of, the stage is thus indicated by the light-emitting element corresponding to one of the hall select switch HSS which is turned on, then the process moves to step  112 . 
     In step  112 , a display control data for the selected stage is written into RAM  20  from the floppy disk, then the process moves to step  114 . 
     In step  114 , head addresses HAD 0  to HAD 3  are set in head address registers ADR 0  to ADR 3 , then the process moves to step  116  as shown in FIG.  4 . 
     In step  116 , an initialized display is indicated in display panel  34 A, then the process moves to step  118 . That is, hall name data HNMD and hall symbol data HSYD are read from RAM  20 , in which the data is a part of the hall characteristic data corresponding to the selected stage, then hall name HNM and hall symbol HSY are indicated in a predetermined position of display panel  34 A based on that data. When hall name data HNMD is read from RAM  20 , a “3” is added to head address HAD 0  which is set in address register ADR 0  to indicate the head address, and then hall name data HNMD is read depending on a value of bytes K 0 . When hall symbol data HSYD is read from RAM  20 , the value of bytes K 0  is added to address “HAD 0 +3” to indicate the head address of hall symbol data HSYD, hall symbol data HSYD is therefore read depending on a value of bytes L 0 . 
     After displaying hall name HNM and hall symbol HSY, musical instrument name data INMD, musical instrument symbol data ISYD, and musical instrument position data (e.g. each value of the x 1  and y 1  values) are read from RAM  20 , and display data for a musical instrument is therefore formed consisting of the musical instrument name INM and musical instrument symbol ISY, both surrounded by musical instrument display frame FLM indicated in display panel  34 A. 
     A plurality of the display data for the next two musical instruments is also formed by similar data as described in the above and indicated in display panel  34 A. 
     Reading the musical instrument data from RAM  20  is described in the case of a musical instrument  1 . The head address is indicated by adding a “3” to head address HAD 1  which is set in address register ADR 1  to read musical instrument name data INMD corresponding to the value of bytes K 1 . This value of bytes Kis added to “HAD 1 +3” to indicate the head address of musical instrument symbol data ISYD, then this musical instrument symbol data ISYD is read depending on the value of bytes L 1 . Each value of the bytes L 1  to M 1  (for tone color indicated by tone color indication data TSD) is also added to an address “HAD 1 +3+K 1 ” to indicate the head address of the musical instrument position data, then each value of the x 1  and y 1  is, in turn, read from RAM  20 . 
     In step  118 , a sound image initialization is executed as shown in FIG. 10 which is described later. 
     In step  120 , a sound image movement described by reference to FIG. 11 is executed, then the process returns to the main routine shown in FIG.  8 . 
     FIG. 10 shows the sound image initialization. 
     In step  122 , reverberation control data RVD is read from RAM  20  to set in reverberation circuit  64 . When reverberation control data RVD is read from RAM  20 , a value of bytes L 0  of hall symbol data HSYD is added to address “HAD 0 +3+K 0 ” to indicate the head address of reverberation control data RVD, then reverberation control data RVD is read depending on the value of bytes of M 0 , then the process moves to step  124 . 
     In step  124 , a “1” is added to control variable register i, then the process moves to step  126 . 
     In step  126 , the process decides whether the value of control variable register i is greater than “3” or not. When this decision is “N”, the process moves to step  128 , otherwise it returns to the subroutine shown in FIG.  9 . 
     In step  128 , tone color indicated data TSD for musical instrument i from RAM  20  is set in sound source control circuit TGi for a number i, where i is any integer. When tone color indicated data TSD is read from RAM  20 , a value of bytes L 1  corresponding to musical instrument symbol data ISYD is added to the address “HAD 1 +3+K 1 ” to indicate the head address of tone color indicated data TSD, then this tone color indicated data TSD is read depending on a value of bytes M 1 , then the process moves to step  130 . 
     In step  130 , a characteristic setting of the musical instrument is executed by a subroutine which is described later by reference to FIG. 12, then the process moves to step  132 . 
     In step  132 , control variable register i is incremented by “1”, then the process returns to step  126  to repeat step  126  to step  132  until control variable i is greater than “3”. 
     When control variable i is greater than “3”, the tone color setting and characteristic setting processes for the three musical instruments are terminated. 
     FIG. 11 shows a subroutine for the sound image movement. 
     In step  140 , the process decides whether musical instrument position data (the x and y coordinates) is indicated in touch panel  34 B, or not. When this decision is “Y”, the process moves to step  142 , otherwise it moves to step  158 . 
     In step  142 , a “1” is added to control variable register i, then the process moves to step  144 . 
     In step  144 , the process decides whether each of the values for the x and y coordinates is indicated within musical instrument display frame FLM or not. When this decision is “Y”, then the process moves to step  146 , otherwise it moves to step  154 . 
     In step  146 , each value of the x and y coordinates is written into storage area Xi and Yi of RAM  20 , respectively, then the process moves to step  148 . 
     In step  148 , the display position of a musical instrument i is changed to a desired position in display panel  34 A corresponding t each value of the Xi and Yi coordinates, then the process moves to step  150 . 
     In step  150 , the characteristic setting is executed by a subroutine which is described later by reference to FIG. 12, then the process moves to step  152 . 
     In step  152 , the process decides whether the musical instrument position data is indicated in touch panel  34 B or not. When this decision is “Y”, then the process returns to step  146  to repeat step  146  to step  152 . Thus, each value of the Xi and Yi coordinates can be changed in response to a touch position of the finger while the finger keeps touching touch panel  34 B and moves to another position in touch panel  34 B to set a desired position of a musical instrument in display panel  34 B. When the decision of step  152  is “N”, the process moves to step  140  to repeat the processes described in the above. 
     After setting the position of musical instrument  1 , if the finger then touches touch panel  34 B to position musical instrument  2 , the decision of step  144  is “N” so that each value of the x and y coordinates is indicated in musical instrument display frame FL of musical instrument  2 . The process therefore moves to step  154 . 
     In step  154 , control variable register i is incremented by “1”, then the process moves to step  156 . 
     In step  156 , the process decides whether control variable i is greater than “3” or not. When this decision is “N”, the process returns to step  144 . 
     On returning to step  144 , the decision is “Y” so that each value of the x and y coordinates is indicated in musical instrument display frame FLM for musical instrument  2 . The position of musical instrument  2  can then be established by executing step  146  to step  152 . 
     Afterwards, if the finger touches touch panel  34 B to position musical instrument  3 , at this time, the decision of step  144  is “N” so steps  154  to  156  have to be executed twice after executing step  140  to step  142 , the process moves to step  146 . Thus, the position of musical instrument  3  can be established by step  146  to step  152 . 
     In touch panel  34 B, when the finger touches an area which is not a part of a musical instrument display frame FLM, the decision of step  156  is “Y”, after executing step  154  three times, then the process returns to step  140 . 
     On the other hand, when the finger does not touch panel  34 B, the decision of step  140  is “N”, then the process moves to step  158 . 
     In step  158 , the process decides whether performance mode switch PMS indicates an on-event or not. When this decision is “N”, then the process returns to step  140 , otherwise it moves to step  160 . 
     Accordingly, if after or before setting the position at least one of three musical instruments  1  to  3 , performance mode switch PMS is turned on, the decision of step  158  is then “Y”, and the process moves to step  160 . 
     In step  160 , a “2” is set in mode register MOD to turn light-emitting element PML on. Thus, the performance mode is changed from the musical instrument position setting mode to the performance reproducing mode, which enables manual performance (or automatic performance) with reproduction of the sound field corresponding to the selected stage. 
     The musical instrument position established in steps  146  to  152  (each of the revised Xi and Yi values) can be transferred to a floppy disk driven by floppy disk unit  24 . FIG. 12 shows a subroutine of the characteristic setting. In step  170 , normalized value P x  which is the result of dividing the value of the x coordinate stored in the storage area Xi by the length W shown in FIG. 3 is set in the storage area Px. In addition, normalized value P y  which is the result of dividing the value of the y coordinate stored in storage area Yi by the length H in FIG. 3 is set in the storage area Py. 
     In step  172 , each value of the P x  and P y  value (contents of Px and Py) is converted into five types of musical tone parameter control information PD (first multiplications constant MP 1  to fourth multiplication constant MP 4 , and filtering constant CF), then a plurality of the data is set in each of parameter controllers CN 1 , CN 2 , and CN 3  shown in FIG.  6 . 
     As a result, in FIG. 10, the sound field of the selected stage is reproduced in response to the data read from RAM  20 . In FIG. 11, the sound field of the selected stage is reproduced in accordance with the positions of musical instruments set by musical instrument position setting device  34 . 
     In this embodiment, touch panel  34 B is used for indicating the musical instrument position, but select elements such as a variable resister, a switch, and the like can be used instead of touch panel  34 B. 
     Also in this embodiment, the stage is selected in combination with the musical instruments, but the stage can also be selected separately from the musical instruments. 
     In addition, in the case where this invention is used for an aqueous performance, the musical instrument position information can be stored in a storage area together with a plurality of performance information so that a sound image can be moved. 
     The preferred embodiment described herein is illustrative and restrictive; the scope of the invention is indicated by the appended claims and all variations which fall within the claims are intended to be embraced therein.