Patent Application
20080184872
This disclosure relates to musical instruments using a digital interface and more specifically to electrical musical tone generation involving note sequence and transposition.
A transposition is the moving of a musical tone from one frequency to another, and minute transpositions are called microtonal. A succession of adjacent microtonal transpositions is called a glissando, and instruments capable of such glissandi are said to have flexible microtonal intonation. The human voice is an example of such an instrument.
Musical harmony is based on the principle of harmonic intervals, or tones occurring simultaneously, which may be represented as a ratio between two frequencies. In music theory, some harmonic intervals are described as pleasant, giving an impression of correctness, coherence or consonance, and others are described as unpleasant, giving an impression of incorrectness, incoherence or dissonance. Psychoacoustic research has found that harmonic intervals are perceived as complex structures by human ears, such that additional frequencies called combination tones are perceived when a given harmonic interval is sounding. The additional tones may be heard at frequencies in specific relationship to the frequencies present in the given harmonic interval. The strongest of these is a so-called Difference Tone (DT) which may be heard at a frequency equal to the difference between the frequencies of the two tones. The flexible microtonal intonation of the human voice allows these complex interval structures to sound correct, coherent, pleasant and consonant.
Fixed pitch instruments such as keyboards were configured to reproduce the concords produced by the flexible microtonal intonation of the human voice within a limited range of transpositions that were considered pleasant sounding, resulting in the twelve key per octave keyboard beginning around 1300 B.C.E. During the renaissance, alternative keyboards were constructed to expand the range of microtonal transpositions that included fourteen key, seventeen key, and thirty-six key per octave keyboards, but the twelve key per octave keyboard remained the dominant keyboard configuration. By the mid-eighteenth century, transposition of the twelve key per octave keyboard was expanded by changing keyboard tuning, which are known as temperaments. Although these keyboard tuning variations allowed a wider range of transposition, uniform purity of microtonal intonation was sacrificed. By the end of the nineteenth century, the use of various temperaments subsided and a tuning known as a twelve tone equal temperament (12ET) became the new popular standard. All interval structures in 12ET are mildly dissonant. In comparison with the flexible microtonal human voice, the fixed structures of 12ET can easily sound incorrect and unpleasant.
In the Twentieth Century, the introduction of electronic instruments created the opportunity for the production of nearly unlimited microtonal transpositions; however, the electronic instruments were expensive, complex, and typically required extension knowledge to program and operate. By 1970 electronic instruments became popular because these instruments were relatively inexpensive and easy to operate. In the early 1980s, a standard digital interface known as Musical Instrument Digital Interface (MIDI) quickly became the most widely used digital interface for electronic musical instruments throughout the world. Although MIDI compatible instruments and accessories have many forms in addition to keyboards, the MIDI data transmission protocol assumes a pitch organization of twelve tones per octave, tuned by default as 12ET. A description of one capability of the general MIDI standard is a Pitch Bend digital message.
A Pitch Bend digital message is a MIDI feature that permits a musician to vary the pitch of the notes being played by typically a whole step up or down from the pitch of the keys played. The musician typically operates the Pitch Bend feature using an analog actuator such as a wheel, joystick, or ribbon control strip. Although Pitch Bend permits a musician to vary the pitch of notes with microtonal transposition in glissando, the Pitch Bend feature does not permit a musician to program a musical instrument to vary individual note pitches without affecting the tuning of other pitches on the same MIDI channel. A keyboard with Pitch Bend capability is shown in Yamaha CBX-K1 MIDI keyboard available from the Yamaha Corporation of America of Buena Park, Calif.
A sequencer is hardware or software tool that records, plays back, and edits MIDI data. Early MIDI sequences were hardware-based, but the term sequencer is now primarily used for software based MIDI sequencers. Some synthesizers and almost all music work stations include a built-in MIDI sequencer. To achieve polyphonic microtonal results using Pitch Bend retuning, multiple tracks are used. An example of a dedicated sequencing software program is Digital Performer available from MOTU, Inc. of Cambridge, Mass.
What is needed is a microtonal tuner that permits a musician, such as an electronic keyboard player, using a fixed pitch instrument with a digital interface, while performing to enhance expression by producing tones perceptible to humans that vary in discrete values from a twelve tone equal tempered octave, allowing unlimited microtonal transposition and the production of pleasant and coherent interval structures.
A microtonal tuner permits a musician, such as an electronic keyboard player using fixed pitch instrument with a digital interface, to enhance performance expression by producing tones perceptible to humans that vary in discrete values from a twelve tone equal tempered octave. The microtonal tuner uses a digital interface, such as a musical instrument digital interface (MIDI), and comprises a digital input, a digital message analyzer, a logic controller, a user input, a user output, a tuning program containing tuning data to create a modified digital message and a digital channel to output the modified digital message to produce a microtonal output. The microtonal output can accommodate any number of notes per octave including tunings such as ¼ Comma Meantone, 19 tone equal temperament, 31 tone equal temperament, Harry Partch's 43-tone tuning, and, 205 tone equal temperament.
A method for microtonal tuning a musical instrument using a digital interface, in another version of the invention, comprises programming a tuning program with microtonal tuning instructions; receiving a digital message for a music instruction; analyzing the digital message to determine the music instruction status; identifying a note-on music instruction status; processing the note-on music instruction status through the tuning program; generating a modified note-on digital message for a microtonal note that varies in a discrete value from a standard twelve equal temperament tuning octave; selecting a digital output channel for the microtonal note digital message; and, outputting the modified note-on digital message on the available digital channel to produce a microtonal note that varies in a discrete value from a standard twelve equal temperament tuning octave.
a shows a microtonal tuner rack-mount front panel embodiment.
b shows a microtonal tuner rack-mount rear panel embodiment.
a shows a major third harmonic interval in traditional music notation.
b shows a root octave transposition in traditional music notation.
c shows a difference tone resulting from a major third interval tuned in equal temperament.
d shows a difference tone resulting from a major third interval tuned in just intonation.
a shows a signal diagram of a one cycle wavelength incidences for two waves in frequency relationship of 4:5.
b shows a signal diagram of three cycles of wavelength incidences for three waves in frequency relationships of 1:4:5.
Fixed pitch musical instruments having digital interfaces are numerous and include keyboard synthesizers and keyboard controllers. In addition to musical instruments having digital interfaces, there are numerous instrument accessories that also have digital interfaces including tone modules, tone samplers, computers, and the like.
Musical instruments having a digital interface generally operate by a musician actuating a musical element that generates an electronic message. A microtonal keyboard controller uses a digital interface, further comprising a keyboard having keys that generate a digital message corresponding to each key that is operated. The electronic message conforms to parameter of a digital interface such as a version of the Musical Instrument Digital Interface (MIDI) that is described in MIDI Medial Adaptation Layer for IEEE-1394 (Nov. 30, 2000). There are currently several specifications of MIDI to include General MIDI Level 1, General MIDI Level 2, and General MIDI lite, and in the future there will likely be more MIDI specifications developed. In addition to current and future versions of MIDI, other digital interfaces for musical instruments that have similar capabilities as MIDI could be used with the microtonal tuner.
Although musical instruments having digital interfaces can permit compatibility among other musical instruments having digital interfaces and accessories, the digital interfaces have tuning limitations. For example assume a keyboard player who wants to perform an expressive improvisation using nineteen equally spaced pitches per octave such as shown in Table 3. Additionally, the player wants to perform music written by the Russian composer Ivan Wyschnegradsky (1893-1979) using thirty-one pitches per octave as shown in Table 4, as well as music written by the American composer Harry Partch (1901-1976) using forty-three unequally spaced pitches per octave as shown in Table 5. None of the desired tunings are unavailable on a standard keyboard. The microtonal tuner 75 allows the player to perform all of this music using a standard electronic keyboard instrument. The player sets up the keyboard and amplification equipment in the usual way, and simply connects a microtonal tuner 75, which contains all of the desired tuning tables in its memory, to the keyboard. Before performing, the desired tuning is simply recalled by the push of a button on the microtonal tuner 75. The player then performs in the usual way on the keyboard, and the microtonal tuner 75 retunes the performance as desired. For each new performance, a different tuning may be used simply by pressing a button to recall the appropriate tuning table on the microtonal tuner 75, allowing the player to easily perform music in a variety of tunings on a single keyboard.
a shows a rack-mount microtonal tuner 75 front panel embodiment, and
One version of the tuning program 115 contains tuning instructions, such as tuning data such as shown in Tables 1-7, or a tuning algorithm such as shown in Formula 1, and is coupled to the logic controller 106 to create a modified digital message for producing a microtonal output in real-time that varies in discrete values from a twelve tone equal tempered octave. The tuning data comprises note number and Pitch Bend data such as shown in Tables 1-7. In some versions of the tuning program 115, the tuning program can be preprogrammed with a program such as: ¼ Comma Meantone shown in Table 2, 19 tone equal temperament shown in Table 3, 31 tone equal temperament shown in Table 4, and, Harry Partch's 43-Tone Tuning shown in Table 5. The modified digital message comprises modified digital messages producing multiple microtonal outputs and each microtonal output can vary independently in pitch from each other microtonal output. Another version of the tuning program 115 contains a tuning algorithm, such as shown in Formula 1, and is coupled to the controller to create a modified digital message for producing a microtonal output in real-time that varies in discrete values from a twelve tone equal tempered octave.
The digital output 123 outputs the modified digital message for producing a microtonal output. In some versions of the invention, the digital output is compatible with a musical instrument digital interface (MIDI). In some versions of the microtonal tuner the modified digital message includes multiple modified digital messages producing multiple microtonal outputs and each microtonal output varies independently in pitch from each other microtonal output.
The dynamic channel allocator 120 (
Some versions of the microtonal tuner 75 can include a tone module 89 for receiving the modified digital message from the digital output 123 to produce an audio output 84 during musical instrument performance. The digital output can be a single digital channel. Some versions of the microtonal tuner 75 can include an analog to digital converter for converting an analog frequency to a note digital message.
The logic controller 106 receives input from user interface input components 107 such as buttons and a rotary encoder, etc., and transmits output to user interface output components 108 such as an LCD, etc. A digital input 109 allows digital messages to be received from external digital hardware and placed in a digital input queue buffer 110, which is managed 111 concurrently with a digital output queue buffer 122 by the logic controller 106. Incoming digital data is analyzed and filtered 112 and nominal messages are handled by the logic controller 106. A tuning program 117 is selected 114 by the logic controller 106 from all available tuning programs 115 through user interaction with user interface input components 107 or by messages received from the digital input 109 from external digital devices. Digital input messages 116 continue from the digital message analyzer/filter 112 to the tuning program 117 from which tuning data or tuning algorithm are retrieved and sent 118 to the digital message constructor/virtual merger 119 which may route the data using a dynamic channel allocator 120, while also merging incoming digital messages 121 which have been passed from the digital input 109 through the digital input queue buffer 110 to the digital message analyzer/filter 112 to the logic controller 106. The resulting messages are prepared in the digital output queue buffer 122, managed by the logic controller 106 for output at the digital output 123.
The version of the tuning program 117 containing tuning data can be programmed with microtonal tuning instructions in a variety of ways. The tuning data comprises a tuning table, note number, and pitch bend data. The version of the tuning program 117 operates as follows. The digital message is received for a musical instruction. The digital message is analyzed to determine the music instruction status. A note-on music instruction status is identified. The music instruction status is processed through the tuning program. A modified note-on digital message is generated for a microtonal note that varies in a discrete value from a standard twelve tone equal temperament tuning octave. A digital output channel is selected for the microtonal note digital message. The microtonal note digital message is outputted on the available digital channel to produce a microtonal note that varies in a discrete value from a standard twelve equal temperament tuning octave.
Some versions of the invention can further comprise receiving the modified note-on digital message on the available digital channel by a synthesizer to produce an audio output during musical instrument performance.
Some versions of the invention can further comprise dynamic channel allocation of a microtonal message for a musical instrument using a digital interface. An available digital output channel is dynamically identified. A digital output channel is selected for the note-on digital message. The digital microtonal note message is sent on the available digital channel.
In one embodiment, the tuning program 117 tuning data comprises a tuning table, note number, and pitch bend data. A tuning program 117 may consist of a tuning lookup table or a tuning algorithm. In a tuning lookup table, a value is retrieved from a memory register according to an incoming index number interpreted as a memory pointer. Any values may be stored in a tuning lookup table, and no calculation is necessary. Stored values can be preformatted as digital messages to be sent to a digital musical instrument, such that no conversion function is required.
A plethora of tunings should be preloaded into the microtonal tuner 75 memory for users to explore easily. Users should also be able to program custom tables for any desired tuning. In addition to user input interface components 107, software may be provided for this purpose. Though a tuning program 117 involves mathematics, user retuning interfaces should emphasize simple and intuitive non mathematical methods of retuning such as moving slider controls or selecting a few parameters to retune an array of keys.
Examples of various tuning data are shown as Tables 1-7. At the top of each chart, the name of a tuning is shown. Seven column headings are divided into three groups. The left group of two bold columns shows the enumeration of input data. Two middle columns show mathematical representations of desired pitches. Three bold columns on the right show retuned data to be output. Reading from left to right on a single row, a given pitch (step) for an input MIDI Note (key), is followed by a mathematical representation of a desired pitch (tone), the distance spanned by this tone in 1/1200 octave units from a common zero point (cents), and the retuned MIDI Note (nn), Pitch Bend LSB (lsb) and Pitch Bend MSB (msb) to be output when this (key) is input.
Table 1 below shows standard 12ET tuning; hence, this table represents the standard tuning which may be compared with other example tunings provided here. Tones (tone) are mathematically defined as increasing fractional n/12 roots of 2, and distances (cents) are shown in increasing steps of 100 cents. The input MIDI Note (key) is the same as the output MIDI Note (nn), each Pitch Bend LSB (lsb) is the default value of 64, and each Pitch Bend MSB (msb) is a default value of 0.
Table 2 below shows the tuning data for ¼ Comma Meantone, the tuning data, which is appropriate for a wide range of Western music written prior to the 18th century. Each input MIDI Note (key) is the same as the output MIDI Note (nn); however, each Pitch Bend LSB (lsb) and Pitch Bend MSB (msb) specifies a pitch unavailable in conventional modern 12ET tuning.
Table 3 below shows tuning data for 19ET tuning that has been advocated by music theorists such as Joseph Yasser because it is close to ⅓ Comma Meantone tuning, and is associated with historical experimental keyboards. In 19ET, tones (tone) are mathematically defined as increasing fractional n/19 roots of 2, and distances (cents) are shown in increasing steps of about 63.16 cents. From top bottom, the input MIDI Note (key) quickly oversteps the output MIDI Note (nn), such that the distance of one octave on a conventional keyboard spans an octave plus a fifth, and each Pitch Bend LSB (lsb) and Pitch Bend MSB (msb) specifies a pitch unavailable in conventional tuning. This is only one method of programming 19ET; many other key assignment arrangements are possible, including those that omit some tones.
Table 4 below shows tuning data for 31ET tuning which has been advocated by music theorists such as Christian Huygens and Adriaan Fokker because it is close to ¼ Comma Meantone tuning, and is also associated with historical experimental keyboards. In 31ET, tones (tones) are mathematically defined as increasing fractional n/31 roots of 2, and distances (cents) are shown in increasing steps of about 21.51 cents. From top bottom, the input MIDI Note (key) very quickly oversteps the output MIDI Note (nn), such that the distance of one octave on a conventional keyboard spans two octaves plus a fifth, and each Pitch Bend LSB (lsb) and Pitch Bend MSB (msb) specifies a pitch unavailable in conventional tuning. This is only one method of programming 31ET; many other key assignment arrangements are possible, including those that omit some tones.
Table 5 below shows tuning data for Harry Partch's 43-Tone JI tuning. From top bottom, the output MIDI Note (nn) is shown to span one octave, while the input MIDI Note (key) spans almost four octaves. Each Pitch Bend LSB (lsb) and Pitch Bend MSB (msb) specifies a pitch unavailable in conventional tuning.
Table 6 below shows tuning data for two consecutive keys in 12ET; this table represents standard tuning data as also shown in (
Table 7 shows tuning data for twelve consecutive keys in 144ET. This table represents a six-fold expansion of pitch resources compared to standard tuning as shown in (
A tuning algorithm requires calculation, and can therefore be more restrictive and more processor intensive than using a tuning data lookup table. The following is an example of a tuning algorithm which maps an incoming note number within an octave divided into 205 equal parts, where n is the note number, f0 is a base frequency and fn is the resulting frequency. Such an algorithm may also require a conversion function to implement fn in a properly formatted digital message to send to a digital musical instrument
Some versions of the method further comprise identifying dynamically an available digital output channel to output the modified digital message for producing a microtonal output. This method comprises identifying dynamically an available digital output channel; selecting a digital output channel for the note digital message; sending the digital microtonal note message on the available digital channel.
a shows a major third harmonic interval in traditional music notation for two tones, which represent a major third interval spelled with two whole notes from C (Root) up to E (Third). The bottom note (Root) is said to be the more important member of the interval.
c shows a an interval in standard tuning (12ET) with difference tone resulting from a major third interval tuned in twelve tone equal temperament, which may produce an undesirable effect and could benefit from retuning. The theoretically correct frequency ratio for an equal tempered major third is 2̂(⅓)/1. So that a comparison may be made between this interval and its retuning, a close approximation is given where the denominator is a power of two, such that the root (Rc) is 8,192 and the third (Tc) is 10,321. The difference tone derived from these frequencies is shown to be 2129 (DTc), which corresponds to tones sounding at nearly one-half step directly above a lower octave transposition, as shown in notation on the staff. Such a sound may be described as unpleasant, giving an impression of incorrectness, incoherence or dissonance.
d shows the difference tone resulting from a major third interval tuned in just intonation and more specifically the combination tones which result from the sounding of the given interval retuned in JI. The frequency ratio for this interval is 5 (Td)/4 (Rd). The difference tone derived from these frequencies is shown to be 1 (DTd), which is said to be the fundamental frequency of a harmonic series which includes both of the harmonic intervals above it. This difference tone sounds exactly at a lower octave transposition, as shown in notation on the staff. Such sounds may be described as pleasant, giving an impression of correctness, coherence or consonance. This is but one example of a retuned interval producing a desirable audible effect.
a shows a signal diagram of a one cycle wavelength incidences for two waves in frequency relationship of 4:5, and
Thus, embodiments of microtonal tuner 75 for a musical instrument using a digital interface are disclosed. One skilled in the art will appreciate that the teachings can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the invention is only limited by the claims that follow.
This application claims priority to U.S. Provisional Patent Application No. 60/817,946 filed Jun. 30, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60817946 | Jun 2006 | US |
