Abstract:
A circular slide attachment with pitch notations and additional markings is provided to enable circular pitch instruments and their indicia to be used for transposing musical keys. In the preferred embodiment of the invention, a circular slide having twelve chromatic scale note indicia is rotatably and coaxially fixed to a thirteen-tone pitch instrument bearing thirteen note indicia. Additional markings affixed to the pitch instrument cooperate with markings on the slide to enable transposition of the notes represented by one set of indicia to the notes represented by the other.

Description:
This non-provisional application for patent claims the benefit of the earlier-filed provisional patent application No. 60/126,538 filed Mar 26, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to the field of music, more specifically to playing or tuning musical instruments or singing music, and more specifically still to changing (i.e. transposing) musical scores or instrument tunings from one key to another. 
     Transposing a musical score involves shifting all the notes in the score up or down one or more half steps on the twelve-tone chromatic scale. This is done most often to allow a singer to sing a song that was not written in his or her vocal range. It is also often done to allow a musician to play a song in a key in which he or she is more proficient on a particular musical instrument, or to play an instrument in which the musical tone designated “A” does not correspond to the standard “A” frequency of 440 Hz. Transposing can be done mentally by counting up or down from each note a given number of half-steps, by mechanical slide rules that shift two chromatic scales opposite one another, or by electronic or digital devices in which one key is the input and the transposed values are the output. The present invention is of the mechanical slide variety of transposers. 
     In a twelve-tone circular reed pitch instrument, each of the twelve tones of the chromatic scale from middle C upward through B can be played by blowing air through any of twelve openings on the periphery of a circular array. In a thirteen-tone reed pitch instrument, an additional high C note is added after B as a convenience. These pitch instruments typically take the form of a small wheel held together by a screw through an axial hole. 
     The note values on a circular pitch instrument are typically printed or embossed as indicia on one face of the wheel next to each peripheral opening at some arbitrary radius from the center. 
     SUMMARY OF THE INVENTION 
     This provisional patent application discloses a circular slide rule transposer in combination with a circular (chromatic) pitch instrument. A circular slide having a radius less than the radius R of the indicia on the face of the pitch instrument, and bearing twelve evenly-spaced indicia of its own inside its periphery, is affixed concentrically to a twelve- or thirteen-tone pitch instrument in which the twelve or thirteen air openings and their indicia are also evenly spaced. Combined with a twelve-tone pitch instrument, the slide can be rotated coaxially by hand relative to the wheel so that each indicium on the slide adjoins a corresponding indicium the on the wheel. If a note X on the slide is placed adjacent to a note Y on the wheel, any other note on the slide will be adjacent its transpose on the wheel. Thus, for example, in transposing a piece in the key of G to the key of B-flat, A transposes to C, D transposes to F, etc. It is therefore an object of this invention to provide a means, in conjunction with a twelve-tone circular pitch instrument, for mechanically transposing notes and keys, and add this means to said pitch instrument with minimal encumbrance and added expense. 
     If a thirteen-tone pitch instrument is used as the wheel, the markings on the pitch instrument itself must be modified in accordance with the present invention to allow it to cooperate with the aforementioned twelve indicia slide in transposing keys. It is therefore a further object of this invention to provide a means, in conjunction with a thirteen-tone circular pitch instrument, for mechanically transposing notes and keys, and add this means to said pitch instrument with minimal encumbrance and added expense. 
     The principal invention herein described, therefore, comprises the slide and its indicia and markings, and other markings needed to be applied to the pitch instrument, which markings in cooperating with each other enable musical keys to be transposed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a typical thirteen-tone circular pitch instrument. 
     FIG. 2 is a perspective view of a twelve-indicium slide for use with either a twelve-tone or thirteen-tone circular pitch instrument. 
     FIG. 3 is a top view of the slide of FIG. 2 (minus indicia). 
     FIG. 4 is a side view of the slide of FIG.  2 . 
     FIG. 5 is a top view of markings, in the preferred embodiment of the present invention, to be applied to the conventional thirteen-tone pitch instrument of FIG. 1 to enable it to cooperate with the slide of FIG.  2 . 
     FIG. 6 is a top view of alternative markings, in a second embodiment of the present invention, to be applied to the conventional thirteen-tone pitch instrument of FIG. 1 to enable it to cooperate with the slide of FIG.  2 . 
     FIG. 7 is an exploded perspective view of the pitch instrument and slide showing the manner of assembly of the preferred embodiment. 
     FIG. 8 is a perspective view of the slide of FIG. 2 mounted on the thirteen-tone pitch instrument of FIG. 1 with markings of FIG. 5 comprising the preferred embodiment of the invention. 
     FIG. 9 is a cross-section of the screw head and surroundings joining the parts of FIG. 8 in slidable engagement. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now in greater detail to the drawings, in which like numerals represent like components throughout the several views, FIG. 1 is a perspective view of a typical thirteen-tone circular pitch instrument  21 , known in the art. It consists of thirteen tone-producing elements (not shown) corresponding to thirteen air openings  1   a ,  1   b ,  1   c , etc. around the periphery of a rigid, usually metal or plastic, wheel  2 . On one face  3  of the wheel  2 , thirteen musical note indicia  4   a,    4   b,    4   c  etc. are affixed near the thirteen openings la, etc., indicating the tone produced by air blown by mouth through a particular opening. In the pitch instrument shown, the tones begin with middle C, progress clockwise to C#, D, Eb, E, F, F#, G, Ab, A, Bb, B, and end at C one octave above the first C. (Alternatively, of course, a pitch instrument may be constructed so that the progression begins with a different pitch, or so that the progression is counterclockwise (not shown) or even so that the progression is random (also not shown).) A screw  5  is shown at the center of the wheel  2  passing through a central hole (not shown). This screw  5  in combination with a nut on the opposite side (not shown) holds the pitch instrument  21  together. For proper function of the pitch instrument, it is immaterial whether the head of screw  5  is on the bottom of the instrument and the nut on top, or vice versa as shown. A circular indented area  6  may be incorporated around the center to shorten the necessary screw length. 
     A twelve-tone circular pitch instrument is identical in all respects to the one shown in FIG. 1 except that there are twelve evenly spaced openings and indicia instead of thirteen. Of course other numbers and progressions of musical tones may be laid out in a circular array, and other means for actuating the tones, e.g., electronic, may be applied to circular pitch instruments, to which non-illustrated embodiments of the present invention may be adapted. 
     FIG. 2 is a perspective view of a twelve-indicium slide  22 , which the present invention comprises, for use with either a twelve- or thirteen-tone pitch instrument. It consists of a thin, approximately circular, piece of rigid material  7  marked with twelve indicia  8   a,    8   b,    8   c  etc. on its upper face  9 . Each indicium is affixed to upper face  9  near the center of 30° wedge-shaped areas  10   a,    10   b,    10   c  etc. corresponding to the twelve tones of the chromatic scale from A to G in (for example) clockwise direction. A hole  11  located at the center is provided for mounting onto the center of the pitch instrument  21  of FIG. 1. A circular depression  12  is incorporated into the material  7  of the slide  22  to match the shape of the indented area  6  in face  3  of the pitch instrument  21  shown in FIG.  1 . This indentation is illustrative of the fact that in order for the slide  22  to fit snugly and slide smoothly about a common axis of pitch instrument  21  against its face  3 , the radial profile of the slide  22  must not interfere with that of the pitch instrument  21 . 
     FIG. 3 is a top view of the slide  22  (minus indicia) better showing the regular spacing of the twelve areas  10   a,  etc. Each area  10   a  etc. is bounded by a short inner edge  13  (making up a portion of the edge of hole  11 ), a first side  14   a,  a second side  14   b,  and an outer edge  15 . Outer ends of sides  14  may be manifested as lines or ridges  16   a  and  16   b  on upper face  9  by printing or casting in material  7  to aid in positioning indicia  8   a,  etc. of FIG. 2 adjacent to indicia  4   a,  etc. of FIG.  1 . Outer edge  15  may be arcuate, or straight (as shown) or other shape for ornamental purposes or to aid in tactile positioning of the slide. 
     FIG. 4 is a side view of the slide  22  showing that its bottom profile  17  matches the shape of indented area  6  and face  3  of the pitch instrument  21  shown in FIG.  1 . 
     FIG. 5 is a top view of a novel set of markings  18   a ,  18   b , . . . ,  18   l , which the preferred embodiment of the present invention comprises. Environmental structure and indicia are dotted lines in the figure, therefore everything shown besides the markings  18  is environmental structure. Outer musical note indicia  4  on the pitch instrument wheel  2  are indicated by large dotted letters “N”. Inner musical note indicia  8  on the slide  22  are indicated by small dotted letters “IN”. The inventive markings  18  are to be affixed to the face  3  of the pitch instrument  21  of FIG.  1 . Wheel  2  of the pitch instrument  21  is indicated in FIG. 5 by a dotted circle. Outer edges  15  and ridges  16  on slide  22  of FIG. 2 are also shown (dotted) in register with markings  18 . The markings  18  in this embodiment form boundaries between adjacent outer indicia  4 . A principal feature of the invention is that the angular separation, measured at the center of wheel  2 , between the outer ends  19   a  through  19   l  of markings  18  is approximately 27.7° ({fraction (1/13)} of a circle), except for the separation between ends  19   l  and  18   a,  which is twice that amount or approximately 55.3°. The inner ends  20   a  through  20   l  of markings  18  are separated by 30° ({fraction (1/12)} of a circle), measured at the center of wheel  2 , so that they can register precisely opposite ridges  16  on the slide  22  of FIG.  2 . Thus the transposition of musical note C, occupying two-thirteenths of wheel  2  of the pitch instrument  21  of FIG.  1  and lying between markings  18   a  and  18   l , will cooperate with any one-twelfth area  10  of the slide  22 . 
     FIG. 6 is a top view of an alternative novel set of markings  29   a,    29   b , . . . , 29   l , which a second embodiment of the present invention comprises. Environmental structure and indicia are dotted lines in the figure; therefore everything shown besides the markings  29  is environmental structure. The inventive markings  29  are to be affixed to the face  3  of the pitch instrument  21  of FIG. 1. A principal feature of this second embodiment is that the markings  29  in this embodiment, unlike the markings  18  of the preferred embodiment of FIG. 5, point toward the centers of the outer indicia  4 , rather than form boundaries between said indicia. The position of the outer ends  31   a  through  31   l  of markings  29  is a point radially just inside each corresponding outer indicium  4 . Thus, the angular distance between outer end  31   a  and  31   b,  measured at the center of wheel  2 , will be approximately 27.7° or {fraction (1/13)} of a circle. So too will be the angular separation of all the other markings  29  except between  31   a  and  31   l , which will be separated by approximately 55.3°. The inner ends  30   a  through  30   l  of markings  29 , however, are separated by 30° ({fraction (1/12)} of a circle) as measured at the center of wheel  2 , so that they can register precisely opposite ridges  16  on the slide  22  of FIG.  2 . Inner ends  30   a  and  30   l  must therefore coincide. Thus the transposition of musical note C, occupying two-thirteenths of wheel  2  of the pitch instrument  21  of FIG.  1  and lying radially just outside outer ends  31   a  and  31   l , will cooperate with any ridge  16  of the slide  22 . 
     FIG. 7 is an exploded perspective view of the pitch instrument and slide showing the manner of assembly of the present invention. Slide  22  is placed against face  3  of pitch instrument  21  and secured by means of screw  5  passing through washer  32  and hole  11  into nut  23 . 
     FIG. 8 is a perspective view of the pitch instrument  21  of FIG. 1 equipped with the preferred embodiment of the present invention, that is, printed with markings  18   a  through  18   l  and assembled slidably and rotatably together with the slide  22  of FIG. 2 using screw  5 . 
     FIG. 9 is an elevational cross-section of assembled screw  5 , washer  32 , hole  11  in slide  22 , and indented area  6  on face  3  of pitch instrument  21 . Note that to permit the slide  22  to rotate slidably coaxially about washer  32  relative to the pitch instrument  21 , the thickness of washer  32  must be greater than slide  22  allowing space  26  above and below the washer  32 , and the washer  32  must be smaller in diameter than hole  11  in slide  22  so that binding does not occur when screw  5  is fully tightened into nut  23  (not shown). 
     A third embodiment of the invention (not shown) is the use of slide  22  of FIG. 2 with a twelve-tone circular pitch instrument (not shown). In this embodiment, no additional markings as shown in FIGS. 5 and 6 are necessary to be applied to the face of the pitch instrument, because twelve indicia on a circular pitch instrument will cooperate with twelve indicia on the slide  22  of FIG. 2 in the absence of other markings.