Electronic musical instrument with programmed accompaniment function

An electronic musical instrument capable of providing automatic bass and chord accompaniments, either in accordance with a program prepared by the player or in immediate response to the depressing of a minimum number of keys on lower and pedal keyboards. The programmed accompaniments proceed sequentially (in steps) with successive measures of accompaniment data being read from a memory. By making some of these measures blank in introducing the accompaniment data into the memory, therefore, the player can play desired bass and chord accompaniments by direct key depression during the blank measures. In an alternative embodiment the production of the programmed accompaniments is automatically inhibited during the production of key-responsive accompaniments, thereby enabling the player to override the programmed accompaniments at any time.

BACKGROUND OF THE INVENTION 
My invention pertains to electronic musical instruments in general and, in 
particular, to those with an automatic accompaniment function. My 
invention is directed more particularly to an electronic musical 
instrument equipped with means for providing automatic bass and chord 
accompaniments in accordance with a program prepared by the player, 
together with means for the insertion, during the progress of the 
programmed accompaniments, of unprogrammed accompaniments in response to 
depressing of the keys on the keyboards used for such accompaniments. 
An assortment of easy-to-play features have been built into the electronic 
musical instrument to enhance its practical utility and to add to the 
enjoyment of performance. Among such features is the programmed 
accompaniment function. If the player inputs a program or data for a 
desired sequence of bass and chord accompaniments, for example, into a 
memory or storage device within the instrument, it will automatically 
sound the programmed bass and chord accompaniments, enabling the player to 
concentrate on playing melodies. 
As heretofore incorporated in the electronic musical instrument, however, 
the programmed accompaniment function possesses one drawback, i.e., the 
total exclusion of the player from the performance of accompaniments. He 
or she cannot in any way take part in the accompaniments during their 
programmed progress. The player must, therefore, cancel the programmed 
accompaniment mode of the instrument, as by the actuation of an 
appropriate switch, for playing some unprogrammed accompaniments in the 
course of the programmed accompaniments. 
SUMMARY OF THE INVENTION 
My invention seeks to overcome the noted drawback of the prior art by 
enabling the player to play a desired accompaniment during the progress of 
a programmed accompaniment. More specifically my invention seeks to enable 
the player to play an automatic (or semiautomatic, to be more exact) 
accompaniment at any time or at preassigned times while the programmed 
accompaniment is in progress. 
Stated in its perhaps broadest aspect, my invention provides an improved 
electronic musical instrument including an accompaniment data memory or 
storage, together with means for introducing a desired sequence of 
accompaniment data into the memory, and means for recovering the 
accompaniment data from the memory in the desired sequence. Also included 
are means for producing an accompaniment both in accordance with the 
accompaniment data being recovered from the memory and in response to 
depressing of the keys of usual keyboard means. 
In some preferable embodiments of my invention the electronic musical 
instrument produces bass and chord accompaniments in response to the 
programmed accompaniment data and also provides automatic bass and chord 
accompaniments when the player depresses a prescribed minimum number of 
keys on lower and pedal keyboards. One recommended practice, therefore, is 
to create a blank or blanks in the sequence of accompaniment data when 
such data are being written on the memory. Then the player can play 
desired automatic bass and chord accompaniments on the pedal and lower 
keyboards during the blank or blanks in the programmed accompaniments. 
It is also possible, as disclosed in an additional embodiment, to prevent 
the production of the programmed accompaniments whenever the player 
depresses keys on the pedal and lower keyboards to play some unprogrammed 
accompaniments. The player can then override the programmed accompaniments 
at any time, without the need for switching the instrument out of the 
programmed accompaniment mode. 
The above and other objects, features and advantages of my invention and 
the manner of attaining them will become more apparent, and the invention 
itself will best be understood, from a study of the following description 
of the preferred embodiments taken together with the attached drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
General 
I will now describe my invention as adapted specifically for an electronic 
musical instrument capable of providing automatic bass and chord 
accompaniments (AUTO BASS/CHORD) in any of three different modes, plus the 
programmed accompaniment function. With reference first to FIG. 1 the 
illustrated electronic musical instrument, generally labeled 10, includes 
an upper keyboard or manual 12, a lower keyboard or manual 14, and a pedal 
keyboard or clavier 16. At 18 is shown a key switch circuit comprising an 
array of key switches (described later in connection with FIG. 3) which 
are to be actuated respectively by the keys in the three keyboards 12, 14 
and 16. The term "keys", as used generically in this specification and in 
the claims appended thereto, should be interpreted to denote not only the 
manual keys of the upper and lower keyboards 12 and 14 but also the pedal 
keys of the pedal keyboard 16. 
The key switch circuit 18 is coupled to a depressed key detector circuit 
20, which functions to detect the depression of the keys in the keyboards 
12, 14 and 16. The depressed key detector 20 can be of the prior art 
design, detecting the depressed keys by the time-division scanning of the 
key switches of the circuit 18 and generating binary-coded information 
(hereinafter referred to as the key information or key data) indicative of 
the depressed keys. The key information consists of, for example: 
1. A four-bit note code representative of that one of the twelve notes in 
each octave which is assigned to each depressed key. 
2. A three-bit octave code representative of that one of several octaves to 
which the note of the depressed key belongs. 
3. A two-bit keyboard code representative of that one of the three 
keyboards 12, 14 and 16 which includes the depressed key. 
By the combination of these note, octave, and keyboard codes the key data 
can represent any individual key in the keyboards 12, 14 and 16. 
The depressed key detector 20 is coupled to a key data channeling circuit 
(channel assigner) 22. The electronic musical instrument 10 is capable of 
sounding a plurality (e.g., twelve) of notes simultaneously, by allotting 
such notes to the corresponding number of different sounding channels 
(tone processing channels). Thus, upon receipt of the key data from the 
depressed key detector 20, the key data channeling circuit 22 assigns each 
note to be sounded to either of the sounding channels. The key data 
channeling circuit 22 can be of the known configuration having a 
12-stage/9-bit shift register. 
Coupled to the output of the key data channeling circuit 22 are an upper 
keyboard (UK) note detector circuit 24, a lower keyboard (LK) note 
detector circuit 26, and a pedal keyboard (PK) note detector circuit 28. 
The key data channeling circuit 22 puts out, on a time-division basis, the 
channeled key data, i.e., the information representative of the depressed 
keys whose notes to be sounded have been assigned to the pertinent 
sounding channels as above. The time-division multiplexed output from the 
key data channeling circuit 22 is fed to the three detectors 24, 26 and 
28. 
The UK note detector 24 is coupled to an upper keyboard (UK) tone generator 
circuit 30. The LK note detector 26 is coupled via a selector 32 to a 
lower keyboard (LK) tone generator circuit 34. The PK note detector 28 is 
coupled via another selector 36 and a bass data generator circuit 38 to a 
pedal keyboard (PK) tone generator circuit 40. 
Receiving the channeled key information from the key data channeling 
circuit 22, the UK note detector 24 derives therefrom only the key data 
pertaining to the notes of the upper keyboard 12, for delivery to the UK 
tone generator 30. The LK note detector 26 likewise derives from the 
channeled key information only the key data pertaining to the notes of the 
lower keyboard 14 and delivers those key data to the LK tone generator 34 
via the selector 32. Also, deriving from the channeled key information 
only the key data concerning the notes of the pedal keyboard 16, the PK 
note detector 28 feeds those key data to the PK tone generator 40 via the 
selector 36 and bass data generator 38. 
The UK tone generator 30, LK tone generator 34, and PK tone generator 40 
create and put out upper keyboard (UK) tone signals, lower keyboard (LK) 
tone signals, and PK tone signals, respectively, in response to their 
input information. These tone generators 30, 34 and 40 can be of the 
familiar make comprising a tone source, tone coloring, and envelope 
generating circuits. 
The outputs of the UK tone generator 30, LK tone generator 34, and PK tone 
generator 40 are coupled via respective mixing resistors 42, 44 and 46 to 
an amplifier 48 and thence to a loudspeaker 50. Thus the UK tone signals, 
LK tone signals, and PK tone signals from the circuits 30, 34 and 40 are 
mixed, amplified, and radiated into the air as audible sounds. 
Automatic Accompaniments 
The electronic musical instrument 10 is furnished with a set of switches 
for selective actuation by the player. These switches are a CUSTOM 
selector switch 52, FINGERED CHORD selector switch 54, SINGLE FINGER 
selector switch 56, PROGRAM PLAY selector switch 58, WRITE switch 60, and 
PROGRAM switch 62. The following is a list of the functions obtainable 
upon activation of these switches: 
CUSTOM Selector Switch 52 
The CUSTOM function, one mode of AUTO BASS/CHORD performance, which 
automatically provides a bass accompaniment on the root note as designated 
by the key which the player depresses on the pedal keyboard 16 and of a 
chord type determined by the type of chord as detected according to the 
depression of the keys on the lower keyboard 14, and a chord accompaniment 
with the notes as designated by the keys which the player depresses on the 
lower keyboard 14. 
FINGERED CHORD Selector Switch 54 
The FINGERED CHORD function, another mode of AUTO BASS/CHORD performance, 
which automatically provides a bass accompaniment with the notes according 
to the root note and the chord type as detected from the depressed keys on 
the lower keyboard, and a chord accompaniment with the notes as designated 
by the keys which the player depresses on the lower keyboard 14. 
SINGLE FINGER Selector Switch 56 
The SINGLE FINGER function, yet another mode of AUTO BASS/CHORD 
performance, which automatically provides bass and chord accompaniments 
with the notes according to the root note as designated by the single key 
which the player depresses on the lower keyboard 14 and according to the 
chord type as designated by the depression or non-depression of the 
"white" or "black" keys on the pedal keyboard 16. 
PROGRAM PLAY Selector Switch 58 
The programmed accompaniment function wherein bass and chord accompaniments 
proceed automatically as dictated by accompaniment data that have been 
written on an accompaniment data memory 64 yet to be described. 
WRITE Switch 60 
The introduction of desired accompaniment data into the accompaniment data 
memory 64. 
PROGRAM Switch 62 
To set the electronic musical instrument 10 into a condition enabling the 
introduction of the accompaniment data into the accompaniment data memory 
64. 
The CUSTOM selector switch 52 is connected to a first input of an AND gate 
66, to a second input of which is connected the PROGRAM PLAY switch 58 via 
an inverter 68. The AND gate 66 puts out a binary CUSTOM signal CA. The 
FINGERED CHORD selector switch 54 is connected to a first input of another 
AND gate 70, to a second input of which is likewise connected the PROGRAM 
PLAY switch 58 via the inverter 68. The AND gate 70 puts out a binary 
FINGERED CHORD signal FC. The SINGLE FINGER selector switch 56 is 
connected to a first input of an OR gate 72, which has its second input 
connected directly to the PROGRAM PLAY switch 58. The OR gate 72 puts out 
a binary SINGLE FINGER signal SF. 
Let it now be assumed that the CUSTOM, FINGERED CHORD, and SINGLE FINGER 
selector swiches 52, 54 and 56 and the PROGRAM PLAY switch 58 are all 
open. Then the CUSTOM signal CA produced by the AND gate 66, the FINGERED 
CHORD signal FC produced by the AND gate 70, and the SINGLE FINGER signal 
SF produced by the OR gate 72 are all in a binary ZERO state. 
The above noted selector 32 is under the control of the SINGLE FINGER 
signal SF. When this signal SF is ZERO as assumed above, the selector 32 
permits the passage therethrough of the output information from the LK 
note detector 26. The other mentioned selector 36 is under the logical OR 
control of the FINGERED CHORD signal FC and SINGLE FINGER signal SF. The 
selector 36 permits the passage therethrough of the output information 
from the PK note detector 28 when both control signals FC and SF are ZERO. 
The electronic musical instrument 10 is further equipped with an AUTO 
RHYTHM function, making it possible to automatically produce a variety of 
rhythm sounds. Provided for this purpose is a rhythm selector switch 
circuit 74 associated with a rhythm pattern memory or storage 76. The 
rhythm selector switch circuit 74 comprises a plurality of rhythm selector 
switches, not shown, the selective activation of which results in the 
production of an output signal indicating the desired rhythm. 
The rhythm pattern memory 76 holds in storage (1) a plurality of rhythm 
patterns RHP corresponding to the respective rhythm selector switches in 
the circuit 74, (2) chord timing signals ACT, (3) bass patterns ABP, and 
(4) arpeggio patterns ARP, with the last three being prepared to conform 
to the respective rhythm patterns RHP. The rhythm patterns RHP provide 
timings for the production of rhythm sounds of various tone colors or 
timbres. The chord timing signals ACT provide timings for the production 
of an automatic chord accompaniment. The bass patterns ABP represent the 
note degree information of the bass note of an automatic bass 
accompaniment with respect to the root note and also provide timings for 
the production of such bass notes. The arpeggio patterns ARP serve to 
select those notes in the chord which are to be automatically sounded in 
arpeggio, and also provide timings for the production of such an 
arpeggiated chord. 
Also coupled to the rhythm pattern memory 76 is a beat counter 78 fed with 
the tempo pulses generated by a tempo pulse generator 80. The rhythm 
pattern memory 76 is addressed both statically by the output from the 
rhythm selector switch circuit 74 and dynamically by the output from the 
beat counter 78. In response to the outputs from the rhythm selector 
switch circuit 74 and the beat counter 78, the rhythm pattern memory 76 
sequentially puts out those rhythm pattern RHP, chord timing signal ACT, 
bass pattern ABP, and arpeggio pattern ARP which correspond to the 
selected rhythm. 
The electronic musical instrument 10 includes means, not shown, for 
inhibiting the production of the chord timing signal ACT and bass pattern 
ABP from the rhythm pattern memory 76 when the three AUTO BASS/CHORD 
selector switches (i.e., the CUSTOM switch 52, FINGERED CHORD switch 54, 
and SINGLE FINGER switch 56) are all open. I further assume that 
provisions are made for preventing the production of the arpeggio pattern 
ARP from the rhythm pattern memory 76 when the player does not choose the 
AUTO ARPEGGIO function. The attached drawings do not show the means for 
the selection of the AUTO ARPEGGIO function since such means are not 
essential for an understanding of my invention. 
The chord timing signal ACT and arpeggio pattern ARP are both impressed to 
the LK tone generator 34. The bass pattern ABP is impressed to the bass 
data generator 38. Derived from the bass pattern ABP, as will be detailed 
presently, a bass timing signal ABT is applied to the PK tone generator 
40. These signals ACT, ARP, ABP and ABT when in a binary ZERO state do not 
affect the performances of the circuits 34, 38 and 40. 
The rhythm pattern memory 76 delivers the desired rhythm pattern RHP to a 
rhythm tone generator 82 coupled to the amplifier 48 via a mixing resistor 
84. The rhythm tone generator 82 comprises means for the production of 
rhythm tones of various timbres, and means for switching the produced tone 
signals with the applied rhythm pattern RHP, thereby producing the desired 
rhythm sound signal. This signal is fed through the mixing resistor 84 and 
amplifier 48 to the loudspeaker 50, which emanates the audible rhythm 
sound into the air. 
For AUTO BASS/CHORD performance, based on either the CUSTOM, FINGERED 
CHORD, or SINGLE FINGER function, the player must activate the desired one 
of the CUSTOM selector switch 52, FINGERED CHORD selector switch 54, and 
SINGLE FINGER selector switch 56. I will discuss these three modes of AUTO 
BASS/CHORD performance under the respective headings. 
AUTO BASS/CHORD Performance--CUSTOM Mode 
Upon closure of the CUSTOM selector switch 52 the CUSTOM signal CA from the 
AND gate 66 becomes binary ONE. The FINGERED CHORD signal FC from the AND 
gate 70 and the SINGLE FINGER signal SF from the OR gate 72 both remain 
ZERO, however. Thus the selector 32 continues to select the output from 
the LK note detector 26, and the other selector 36 also continues to 
select the output from the PK note detector 28. 
Following the activation of the CUSTOM selector switch 52 the player may 
proceed to depress a plurality of keys on the lower keyboard 14 to 
constitute a chord. He or she is also supposed to depress, on the pedal 
keyboard 16, a single key whose note is to become the root of the bass 
accompaniment to be produced automatically. As the key data channeling 
circuit 22 puts out the corresponding channeled key information as 
aforesaid, the LK note detector 26 derives therefrom the key data 
pertaining to the depressed keys of the lower keyboard 14 and feeds them 
to the LK tone generator 34 via the selector 32. In response to the input 
information the LK tone generator 34 generates tone signals representative 
of the chord constituent notes according to the depressed lower keys. The 
circuit 34 puts out the thus generated tone signals in synchronism with 
the chord timing signal ACT fed from the rhythm pattern memory 76, in such 
a way that the chord timing signal "triggers" or renders the tone signals 
at predetermined intervals. Thus the chord constituent tones are 
automatically sounded in a rhythmic fashion to provide a chord 
accompaniment. 
The PK note detector 28 derives from the channeled key information a key 
data indicating the single depressed key of the pedal keyboard 16, 
delivering that data to the selector 36. Since the FINGERED CHORD signal 
FC and SINGLE FINGER signal SF are now both ZERO, the selector 36 permits 
the passage therethrough of the output from the PK note detector 28 to the 
bass data generator circuit 38. This circuit 38 receives not only the 
output from the PK note detector 28 but also the output from the LK note 
detector 26, via the selector 32, and the bass pattern ABP from the rhythm 
pattern memory 76. 
Supplied with such inputs, the bass data generator circuit 38 generates, in 
accordance with the bass pattern ABP, the necessary coded information 
representative of the desired bass notes consisting of the root note 
selected on the pedal keyboard 16 and the notes, subordinate to the root, 
determined in accordance with the chord type selected by the player by the 
depression of the lower keys. For further details about the construction 
and operation of this bass data generator circuit 38, reference is 
directed to the U.S. Pat. No. 4,184,401, under the title of "Electronic 
Musical Instrument with Automatic Bass Chord Performance Device", issued 
to Teruo Hiyoshi, et al. and assigned to the assignee of the instant 
application. 
The bass data generator circuit 38 delivers to the PK tone generator 40 its 
output data indicative of the successive bass notes of the root note and 
the subordinate notes to be sounded. The PK tone generator 40 generates 
the corresponding tone signals in response to the input data and puts out 
the tone signals in synchronism with the incoming bass timing signal ABT. 
Although not illustrated, means are provided in this electronic musical 
instrument 10 for forming the bass timing signal ABT from the bass pattern 
ABP produced by the rhythm pattern memory 76. The bass timing signal ABT 
is timed with the bass pattern ABP. Thus the instrument 10 automatically 
produces, in timed relationship to the bass pattern ABP, the desired 
accompaniment of bass tones only the root of which is being selected by 
the player on the pedal keyboard 16 and which correspond to the type of 
the chord being played on the lower keyboard 14. 
AUTO BASS/CHORD Performance--FINGERED CHORD Mode 
The player may activate the FINGERED CHORD selector switch 54 for AUTO 
BASS/CHORD performance in the FINGERED CHORD mode, which provides 
automatic bass and chord accompaniments as he or she simply depresses some 
chord constituting keys on the lower keyboard 14. Upon closure of the 
FINGERED CHORD selector switch 54 the FINGERED CHORD signal FC from the 
AND gate 70 becomes binary ONE, whereas the SINGLE FINGER signal SF from 
the OR gate 72 remains ZERO. Consequently, although the selector 32 
continues to permit the passage therethrough of the output from the LK 
note detector 26, the other selector 36 becomes switched to permit the 
passage therethrough of the output from a root note detector 86 connected 
between itself and the output of the LK note detector 26. 
Like the selector 36 the root note detector 86 is under the logical OR 
control of the FINGERED CHORD signal FC and SINGLE FINGER signal SF, 
becoming operative when the logical OR conditions are met by the two 
control signals. On receipt of the output information from the LK note 
detector 26 the root note detector 86 detects the root note of the chord 
composed of the notes of the keys being depressed by the player on the 
lower keyboard 14. The root note detector 86 puts out the binary-coded 
information representative of the detected root note. The aforementioned 
U.S. Pat. No. 4,184,401 discloses a circuit similar in function to the 
root note detector 86. 
The bass data generator 38 receives (1) the output from the LK note 
detector 26 via the selector 32, (2) the output from the root note 
detector 86 via the selector 36, and (3) the bass pattern ABP from the 
rhythm pattern memory 76. In response to these inputs the bass data 
generator 38 delivers to the PK tone generator 40 the output data 
representative of the successive bass notes of the root note and the 
subordinate notes to be sounded. The operation of the bass data generator 
38 during AUTO BASS/CHORD performance in the FINGERED CHORD mode is 
analogous with that during performance in the CUSTOM mode. The only 
exception is that in the FINGERED CHORD mode, the circuit 38 derives the 
root note data from the output from the root note detector 86, instead of 
from the output from the PK note detector 28 as in the CUSTOM mode. 
It is thus seen that the chord selected by the player on the lower keyboard 
14 is sounded together with the bass tones based on the bass pattern ABP. 
As in the CUSTOM mode the LK tone generator 34 receives the chord timing 
signal ACT thereby to control the production timing of the chord with the 
selected rhythm and hence to sound the chord rhythmically. The bass timing 
signal ABT fed to the PK tone generator 40 also makes it possible to 
produce the bass accompaniment in the desired rhythm. 
AUTO BASS/CHORD Performance--SINGLE FINGER Mode 
AUTO BASS/CHORD performance in the SINGLE FINGER mode is such that the 
electronic musical instrument 10 provides automatic bass and chord 
accompaniments in response to the depression of a single lower key. The 
player is further required, however, to designate some desired one of a 
plurality (e.g., three) of kinds of chord types by depressing (or not 
depressing) the "white" or "black" keys of the pedal keyboard 16. The 
designation of any desired type of chord leads to the production of coded 
data for automatic production of the corresponding bass and chord 
accompaniments. 
The player may actuate the SINGLE FINGER selector switch 56 for the SINGLE 
FINGER function. The SINGLE FINGER signal SF from the OR gate 72 becomes 
binary ONE upon closure of the SINGLE FINGER selector switch 56. Thereupon 
the selector 32 is switched to permit the passage therethrough of the 
output from a subordinate note data generator 88 connected between itself 
and the output of the LK note detector 26. The other selector 36 permits 
the passage therethrough of the output from the root note detector 86 as 
in the FINGERED CHORD mode. 
The PK note detector 28 derives from the channeled key information from the 
key data channeling circuit 22 the key data concerning the pedal keyboard 
16, for delivery to a chord discriminator circuit 90. This circuit 90 puts 
out either of three chord type designation signals, i.e., a "major" signal 
Mj, a "minor" signal mi, and a "seventh" signal 7th, depending upon the 
input information. In the illustrated embodiment the chord discriminator 
circuit 90 produces: 
1. The "seventh" signal 7th, specifying a dominant seventh chord, when the 
player depresses a "white" pedal key. 
2. The "minor" signal mi, specifying a minor triad chord, when the player 
depresses a "black" pedal key. 
3. The "major" signal Mj, specifying a major chord, when the player presses 
neither "white" nor "black" pedal keys. 
The chord discriminator circuit 90 delivers these chord type signals Mj, mi 
and 7th to the subordinate note data generator 88. Actuated by the SINGLE 
FINGER signal SF from the OR gate 72, the subordinate note data generator 
88 produces the data representative of the constituent notes of the chord 
to be sounded, in accordance with the input information (indicating the 
note of single depressed lower key) from the LK note detector 26 and with 
either of the three chord type signals Mj, mi and 7th from the chord 
discriminator circuit 90. The subordinate note data generator 88 can be of 
known configuration comprising a subordinate note processing data 
generator circuit, adders, etc. 
The subordinate note data generator 88 puts out, on a time-division 
principle, the binary-coded data representative of the constituent notes 
of the chord, for delivery to the LK tone generator 34 via the selector 
32. The tone generator 34 also receives the chord timing signal ACT from 
the rhythm pattern memory 76, so that the chord is automatically sounded 
in the selected rhythm. 
The subordinate note data generator 88 also supplies its output data to the 
bass data generator 38 via the selector 32. The root note detector 86 also 
delivers its output to the bass data generator 38 via the selector 36. The 
root note detector 86 is so constructed, as has been known heretofore, 
that during operation in the SINGLE FINGER mode, it gives priority to the 
lowest-note key depressed on the lower keyboard 14 in producing its output 
data. In the present instance, since a single lower key is being pressed, 
the root note detector 86 puts out the data representative of its note, 
which is to be used as the root note of the desired bass accompaniment. 
Thus the bass data generator 38 produces the data representative of the 
bass notes whose root note is the note of the single depressed lower key 
and which correspond to the selected one of the major, minor and seventh 
chords. It is of course understood that the bass data generator 38 has 
processed the bass notes in accordance with the applied bass pattern ABP. 
Receiving the bass data from the bass data generator 48, the pedal 
keyboard tone generator circuit 40 puts out the corresponding bass tone 
signal in synchronism with the bass timing signal ABT. 
AUTO ARPEGGIO Effect 
When the player chooses the AUTO ARPEGGIO effect, the rhythm pattern memory 
76 delivers the arpeggio pattern ARP to the LK tone generator 34. In 
response to the arpeggio pattern ARP the LK tone generator 34 selects the 
successive ones of chord constituent notes, whose data are being fed via 
the selector 32, and transforms such notes into arpeggiated tone signals 
in accordance with the arpeggio pattern ARP. Thus the notes played on the 
lower keyboard 14 are automatically sounded in arpeggio. No more detailed 
explanation of the AUTO ARPEGGIO function will be necessary because it 
does not form a feature of my invention. 
Programmed Accompaniments 
The following is the discussion of the way in which desired accompaniment 
data are introduced into the accompaniment data memory 64 for programmed 
accompaniments. Of the "writable" type, preferably a random access, the 
accompaniment data memory 64 is intended to store a plurality of measures 
(or bars) of accompaniment data, in an order corresponding to the sequence 
of such measures. In this particular embodiment the accompaniment data 
stored in the memory 64 are of identical character with those used during 
AUTO BASS-CHORD performance in the SINGLE FINGER mode. Thus the 
accompaniment data in the successive storage locations of the memory 64 
represent the notes of individually depressed lower keys, which are to be 
used as the roots, and the types of the chords selected by the pedal 
keyboard 16. 
The introduction of such desired accompaniment data into the memory 64 
requires the manipulation of the WRITE switch 60 and PROGRAM switch 62, as 
well as of the lower and pedal keys. The WRITE switch 60 is coupled, on 
one hand, to a two-word-to-one-word converter 92 (hereinafter referred to 
simply as the word converter) via a decay differentiating circuit 94 and, 
on the other hand, to a first input of an AND gate 96. The second input of 
this AND gate 96 is coupled to the PROGRAM switch 62, and its output to 
the write control input WT of the accompaniment data memory 64. The 
PROGRAM switch 62 is further connected to a first input of an AND gate 98 
via an inverter 100 and also to an attack differentiating circuit 102. The 
AND gate 98 has its second input coupled to the beat counter 78 and its 
output to a first input of an OR gate 104. This OR gate 104 has its second 
input connected to the decay differentiating circuit 94 and its output to 
a measure counter 106. The output of this measure counter is coupled both 
to the accompaniment data memory 64 and to a display 108. 
The player may first activate the PROGRAM switch 62 for writing desired 
accompaniment data onto the memory 64. Upon closure of the PROGRAM switch 
62 the AND gate 98 functions to inhibit the application of the "carry" 
signal from the beat counter 78 to the measure counter 106. Further the 
measure counter 106 is reset by the output from the attack differentiating 
circuit 102 which senses the attack of the output from the PROGRAM switch 
62. The parallel bit output from the measure counter 106 now designates 
that address in the memory 64 where the first measure of accompaniment 
data are to be stored. 
The player may proceed to select a desired root note on the lower keyboard 
14 and a desired type of chord on the pedal keyboard 16. As those of the 
key switches in the circuit 18 which correspond to the depressed keys 
become closed, the keying sensor circuit 20 time-dividedly puts out the 
corresponding key data, for delivery to the word converter 92 connected 
between the circuit 20 and the accompaniment data memory 64. The word 
converter 92 acts to translate from the two-word into one-word formate the 
key data (pertaining to the pressed lower key and, possibly, pedal key) 
from the keying sensor circuit 20. 
FIG. 2 shows a typical configuration of the work converter 92. The 
exemplified word converter 92 comprises two latching circuits 110 and 112 
receiving the key data from the depressed key detector 20. The first 
latching circuit 110 has a strobe input S coupled to an AND gate 114. This 
AND gate 114 receives (1) the output from a NOR circuit 116 and (2) a 
lower keyboard signal LK indicative of those output data from the 
depressed key detector 20 which concern the lower keyboard 14. The NOR 
circuit 116 is coupled to the bit outputs of the latching circuit 110. 
The second latching circuit 112 also has a strobe input S connected to an 
AND gate 118 receiving (1) the output from a NOR circuit 120 and (2) a 
pedal keyboard signal PK. The NOR circuit 120 is coupled to the bit 
outputs of the second latching circuit 112. The pedal keyboard signal PK 
is suggestive of those output data from the depressed key detector 20 
which pertain to the pedal keyboard 16. 
It is thus seen that the first latching circuit 110 latches the key data on 
the depressed keys of the lower keyboard 14, whereas the second latching 
circuit 112 latches the key data on the depressed keys of the pedal 
keyboard 16. The latching circuits 110 and 112 deliver the desired 
accompaniment data of one-word format to the accompaniment data memory 64. 
I believe it easy for the specialists to devise means for deriving the 
lower keyboard signal LK and pedal keyboard signal PK from the mentioned 
keyboard code included in the key data from the depressed key detector 20. 
Now the player may activate the WRITE switch 60. The binary ONE signal 
generated upon closure of the WRITE switch 60 is impressed to the write 
control input WT of the accompaniment data memory 64 via the AND gate 96. 
Thereupon the accompaniment data are admitted into and stored in the 
memory 64 from the word converter 92. 
Upon subsequent opening of the WRITE switch 60 the decay differentiating 
circuit 94 connected thereto delivers an output to the reset terminals R, 
FIG. 2, of the latching circuits 110 and 112 in the word converter 92, for 
clearing these circuits. The differentiating circuit 94 also supplies its 
output to the measure counter 106 via the OR gate 104, thereby causing the 
measure counter to count up and specify the next address in the memory 64 
for the storage of the next measure of accompaniment data. 
The repetition of the foregoing cycle of operation makes it possible to 
introduce a desired number of measures of accompaniment data into the 
memory 64. The measure counter 106 feeds its output not only to the memory 
64 but also to the display 108. Thus, with the progress of the writing 
operation, the display 108 makes visual presentation of the number of 
measures that have been introduced into the memory 64. 
For performance with automatic accompaniments in accordance with the data 
stored in the memory 64, the player may open the PROGRAM switch 62 and 
close the PROGRAM PLAY switch 58. Upon opening of the PROGRAM switch 62 
the AND gate 98 becomes operative to permit the application of the carry 
signal (i.e., "measure" pulses) from the beat counter 78 to the measure 
counter 106. The closure of the PROGRAM PLAY switch 58 results in the 
application of a binary ONE signal to a gating circuit 122 thereby causing 
conduction therethrough, with the gating circuit 122 being connected 
between the memory 64 and two decoders 124 and 126 coupled to the key 
switch circuit 18. 
The binary ONE signal from the PROGRAM PLAY switch 58 is further impressed 
to the OR gate 72, so that the SINGLE FINGER signal produced by this OR 
gate becomes binary ONE. The inverter 68 inverts the binary ONE signal 
from the PLAY switch 58 as it is applied to the AND gates 66 and 70, with 
the result that the CUSTOM signal CA and FINGERED CHORD signal FC remain 
binary ZERO. It is thus seen that the activation of the PROGRAM PLAY 
switch 58 leads to the automatic conditioning of the electronic musical 
instrument 10 for the SINGLE FINGER mode. 
AS the PROGRAM switch 62 is now open as aforesaid, the beat counter 78 
drives the measure counter 106 by its output "measure" pulses. In step 
with such driving of the measure counter 106 the accompaniment data memory 
64 puts out the desired accompaniment data (concerning the lower keyboard 
14 and pedal keyboard 16). The accompaniment data are applied via the 
gating circuit 122 to the two decoders 124 and 126, which function to 
decode the input data into key signals corresponding to the individual 
keys of the lower keyboard 14 and to the individual keys of the pedal 
keyboard 16, respectively, for application to the key switch circuit 18. 
The key switch circuit 18 includes field-effect transistor gates connected 
in parallel with the respective key switches corresponding to the keys of 
the lower keyboard 14 and with the respective key switches corresponding 
to the keys of the pedal keyboard 16, as will be detailed subsequently. 
The key signals from the decoders 124 and 126 can cause conduction through 
the corresponding field-effect transistor gates. Conduction of any 
field-effect transistor gate, therefore, is functionally equivalent to the 
closure of the key switch connected in parallel therewith and, 
consequently, to the pressing of the corresponding lower or pedal key. 
FIG. 3 is a fragmentary schematic of the key switch circuit 18, showing 
only the key switches KSW.sub.1i, KSW.sub.2i, . . . KSW.sub.12i, as well 
as associated means, corresponding to the twelve "white" and "black" keys 
C, C.music-sharp., . . . B of the lower keyboard 14 forming an arbitrary 
octave i. The twelve key switches of the octave i are connected, via 
respective diodes D.sub.1i, D.sub.2i, . . . D.sub.12i, at the 
intersections of lines n.sub.1, n.sub.2, . . . n.sub.12 corresponding to 
the twelve notes C through B and a line B.sub.i corresponding to the 
octave i, with the note and octave lines forming a matrix. The key 
switches KSW.sub.1i through KSW.sub.12i are connected in parallel with the 
noted field-effect transistor gates G.sub.1i, G.sub.2i, . . . G.sub.12i 
respectively. 
Applied separately to the field-effect transistor gates G.sub.1i through 
G.sub.12i are the key signals from the decoder 124 for causing selective 
conduction therethrough. The keying sensor circuit 20 senses any closed 
key switch by the time-division scanning of the lines n.sub.1 through 
n.sub.12 and the line B.sub.i. As has been pointed out, the conduction of 
any field -effect transistor gate, due to the key signal from the decoder 
124, is equivalent to the closure of the key switch connected in parallel 
therewith. Consequently the depressed key detector 20 puts out information 
representative of the single selected lower key corresponding to the 
conductive gate. The foregoing description of FIG. 3 applies to the key 
switches and associated means corresponding to the lower keys of other 
than the octave i and to all pedal keys. 
The depressed key detector 20 thus puts out the key data on the selected 
lower key and pedal key. On receipt of the key data the key data 
channeling circuit 22 assigns the notes of the selected keys to suitable 
sounding channels. The LK note detector 26 and PK note detector 28 
subsequently derive from the channeled key data the key data representing 
the lower and pedal keys, respectively. The electronic musical instrument 
10 processes the outputs from the circuits 26 and 28 just as it does 
during AUTO BASS/CHORD performance in the SINGLE FINGER mode, providing 
automatic bass and chord accompaniments based on the roots represented by 
the output data of the LK note detector 26 and on the types of chords 
represented by the output data (i.e. no key, white key or black key) of 
the PK note detector 28. 
It will now be clear that the programmed accompaniments in accordance with 
my invention proceed in conformity with the accompaniment data being read 
from the memory 64 in steps (sequentially) with the output from the 
measure counter 106. If the player depresses some desired lower and pedal 
keys during the progress of such programmed accompaniments, the 
corresponding key switches in the circuit 18 will close individually, as 
is apparent from FIG. 3. The player may therefore temporarily deviate from 
the programmed accompaniments and play some AUTO BASS/CHORD accompaniments 
in the SINGLE FINGER mode by selecting desired roots and desired types of 
chords on the lower and pedal keyboards 14 and 16. 
For such temporary deviation from the programmed accompaniments a desired 
measure or measures may be made blank in introducing the successive 
measures of accompaniment data into the memory 64. The player is then free 
to play desired AUTO BASS/CHORD accompaniments during such a blank measure 
of measures. The display 108 visually represents the number of measures 
being played, by receiving the output from the measure counter 106. The 
player may therefore recognize the blank measure or measures from the 
display 108 and play AUTO BASS/CHORD accompaniments of his or her choice 
during the blank measure or measures. 
Second Form 
FIG. 4 shows another preferable form of the electronic musical instrument 
in accordance with my invention. Since most parts or components of this 
modified instrument, generally designated 10a, can be identical in 
construction and function with the corresponding parts of the preceding 
embodiment, I will identify such corresponding parts by like reference 
numerals. 
The electronic musical instrument 10a differs from the instrument 10 of 
FIG. 1 in that, first of all, the outputs of the depressed key detector 20 
and the accompaniment data memory 64 are both coupled to the key data 
channeling circuit 22 via an OR gate 150. The depressed key detector 20 
delivers the key data to the channeling circuit 22 directly through the OR 
gate 150. The accompaniment data memory 64, on the other hand, supplies 
the accompaniment data to the key data channeling circuit 22 via a 
one-word-to-two-word converter circuit 152 (hereinafter referred to as the 
1W/2W converter, in contradistinction to the 2W/1W converter 92), the 
gating circuit 122 and the OR gate 150. 
In view of the fact that the depressed key detector 20 and accompaniment 
data memory 64 may produce their outputs simultaneously during the closure 
of the PROGRAM PLAY switch 58, a timing signal generator circuit 154 is 
provided for causing the circuit 20 and memory 64 to put out the desired 
data at different moments in time. The timing signal generator circuit 154 
generates two timing signals T1 and T2, FIG. 5, of inverse relationship to 
each other. The circuit 154 delivers these timing signals T1 and T2 to the 
"enable" terminals E of the accompaniment data memory 64 and the depressed 
key detector 20 via OR gates 156 and 158 respectively. 
Each binary ONE state of the timing signal T1 lasts for a length of time 
(e.g., 96 microseconds) sufficient for the accompaniment data memory 64 to 
put out one word. The other timing signal T2, on the other hand, remains 
in each binary ONE state for a length of time sufficient for the depressed 
key detector 20 to complete one scanning cycle of the key switch circuit 
18. Thus, in response to the two timing signals T1 and T2, the depressed 
key detector 20 and accompaniment data memory 64 alternately operate in a 
time-division multiplexed manner. There is accordingly no likelihood of 
the depressed key detector 20 and accompaniment data memory 64 
concurrently delivering their outputs to the key data channeling circuit 
22. 
The other input of each of the OR gates 156 and 158 is coupled to the 
PROGRAM PLAY switch 58 via an inverter 160. As long as the PROGRAM PLAY 
switch 58 is open, therefore, the depressed key detector 20 and 
accompaniment data memory 64 are capable of continuous operation, being 
unaffected by the timing signals T1 and T2. 
It will be recalled that the accompaniment data stored in the memory 64 are 
of one-word format. As they are sequentially recovered from the memory 64, 
therefore, the accompaniment data must be translated into two word key 
data representing the depressed lower and pedal keys, prior to delivery to 
the key data channeling circuit 22. The 1W/2W converter 152 serves this 
purpose. The other details of configuration of this modified instrument 
10a can be as set forth above in connection with the instrument 10 of FIG. 
1. 
For performance with programmed accompaniments on the modified electronic 
musical instrument 10a, the player may open the PROGRAM switch 62 and 
close the PROGRAM PLAY switch 58. Thereupon the memory 64 puts out the 
one-word accompaniment data, as dictated by the output from the measure 
counter 106. The 1W/2W converter 152 transforms the one-word accompaniment 
data into the corresponding two-word key information as aforesaid and 
feeds the key information to the channeling circuit 22 via the gating 
circuit 122 and OR gate 150. The musical instrument 10a is thus enabled to 
make automatic, programmed accompaniments based on the SINGLE FINGER mode, 
with the roots of such accompaniments being selected by the lower keyboard 
14 and with the three available types of chords being selected by the 
pedal keyboard 16. I have already explained, in connection with FIG. 1, 
the programmed accompaniment function in the SINGLE FINGER mode, so that 
no more description will be necessary on this subject. 
The modified electronic musical instrument 10a also permits the player to 
play some desired AUTO BASS/CHORD accompaniments during the progress of 
the programmed accompaniments. Upon depression of desired lower and pedal 
keys in the course of the programmed accompaniments, the corresponding key 
switches in the circuit 18 will close, with the result that the depressed 
key detector 20 puts out the key data denoting the depressed keys. The key 
data are directed via the OR gate 150 to the key data channeling circuit 
22, which assigns the incoming key data to some appropriate sounding 
channels. Thus the player can select, on the lower and pedal keyboards, 
the desired root notes and desired kinds of chords necessary for the 
production of AUTO BASS/CHORD accompaniments in the SINGLE FINGER mode 
during performance with the programmed accompaniments. 
The programmed accompaniments and the uprogrammed AUTO BASS/CHORD 
accompaniments should not take place at the same time, however. As in the 
preceding embodiment, therefore, the programmed accompaniment data in the 
memory 64 should include a blank measure or measures, during which the 
player can play some desired AUTO BASS/CHORD accompaniments. 
Modifications 
While I have herein shown and described my invention in what I have 
conceived to be the most practical and preferred embodiments, it is 
recognized that modifications thereof may be made within the scope of my 
invention. Typical of such possible modifications is the phantom gating 
circuit 170, FIG. 4, connected between gating circuit 122 and OR gate 150. 
The gating circuit 170 becomes nonconductive in response to a control 
signal delivered from the depressed key detector 20 when any of the lower 
and pedal keys is pressed. The memory 64 is therefore unable to supply the 
programmed accompaniment data to the OR gate 150 when the player presses 
any lower and pedal keys to play some desired AUTO BASS/CHORD 
accompaniments during the progress of programmed accompaniments. The 
gating circuit 170 enables the player to override the programmed 
accompaniments. He may play desired AUTO BASS/CHORD accompaniments at any 
time, even if the programmed accompaniment data in the memory 64 contain 
no blanks. 
I realize that certain additional modifications may well occur to one 
skilled in the art within the broad teaching hereof. It is my intention, 
therefore, that the scope of protection afforded hereby shall be limited 
only insofar as such limitations are expressly set forth in the appended 
claims.