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the Virtual Monochord: help

the Virtual Monochord allows you experiment with alternate tunings. you specify a scale (a series of pitches in an octave) and a simple score (a series of notes and chords). the Virtual Monochord then performs your score using your scale, and gives you an audio (WAV) file of the performance. the Monochord is not intended as a compostion tool; for example, you have no to specify a rhythm or tempo. it is, however, a handy way to compare, for example, the sound of a cadence in equal and just tempered scales, or get a feel for a melody using a Thai pentatonic scale based on seven tones per octave.

change the four fields (base, scale, mode, and score) as you see fit, and then press the go button. when the page reloads, use the new audio link to play or save the created audio file.

the preset buttons set the fields to some interesting values. they also provide examples of more complex scales and scores.

using the Monochord may seem confusing at first. the best way to figure it out is to play with it. try changing just one field at a time at first, for example, change the just the mode, or just the score. the scale field is the most complex, but it is also the most rewarding, since it allows you to create and compare different tunings.

The base is the frequency in Hertz of the reference note (1:1) for your scale. for example, 440 starts your scale at standard western middle "A".

The scale specification is a string consisting of a set of pitch specs separated by white space. The resulting scale will be sorted in order of ascending frequency. A pitch spec comes in one of three forms:

ratio

A ratio is specified by two integers separated by a colon. For example

  3:2

specifies a pitch with a frequency 1.5 times the base frequency (a natural fifth).

float

A float is specified by a floating point number; it must contain a decimal point. For example

  1.495

specifies a pitch with a frequency 1.495 times the base frequency (a quarter-comma meantone fifth).

equal

An equal tempered pitch is specified by an integer specifiying the number of degrees, the the letter "E", and an integer indicating which degree. If the second integer is omitted, all notes in the equal tempered scale are generated. For example

  12E7

specifies a pitch with a frequency 1.498 times the base frequency (a 12-tone equal-tempered fifth), and

  12E

generates an entire 12-tone equal-tempered scale.

Sets the mode of the score. This effectively adds an offset to the scale degrees listed in the score. Note that this only works as expected with scales with unequal intervals (eg. a diatonic or pentatonic scale); with equally spaced scales (eg. a chromatic scale), it simply shifts the pitch of the score. For example, with a standard diatonic scale, you could produce a Dorian mode scale with either of the following:

  mode:  1 (default)
  score: 3 5 6 8 10 12 13 15

or

  mode:  2
  score: 1 3 4 6 8 10 11 13

The score specification consists of a series of event specifications, separated by white space. An event specification is one or more integers separated by slashes, where each integer indicates a scale degree, and multiple scale degrees indicates a chord. The scale degree is the number of the pitch in the scale. Remember that the scale is sorted by ascending pitch, not by the order that the pitches were listed in the scale specification.

Values greater than the number of scale degrees are allowed, and do the expected thing by extending the scale beyond of the base octave. Negative values are not allowed; if the resulting pitches are too high consider lowering your base frequency.

There is no rhythmic notation; every event takes the same amount of time.

For example:

  scale: 12E
  score: 1 3 5 6 8 10 12 13

is a 12-tone equal-tempered major scale, and

  scale 9:8 5:4 4:3 3:2 5:3 15:8
  score: 1/5/8 6/10/13 8/12/14

is a just-tempered I/IV/V progression.

The instrument option selects one of a small set of timbres to use in generating your audio. These timbres are synthesized via simple csound instruments, and are not intended to be realistic. However, since the instruments differ in the relative strengths of their overtones, they will "bring out" different aspects.

The instrument specifications are adapted from the Amsterdam Catalog of CSound Intruments.

simple

a sine wave with no envelope. good for hearing basic pitch relationships, but the lack of overtones makes non-harmonic intervals harder to distinguish.

pluck

a simulation of a plucked string using the Karplus/Strong algorithm. features strong higher harmonics that decay rapidly.

brass

a simulation of a brass instrument using frequency modulation. the relationship between the carriers is 1:1, producing harmonic overtones.

reed

a simulation of a reed instrument using frequency modulation. the relationship between the carriers is 1:2, producing harmonic overtones with an emphasis on the odd harmonics.

The audio is generated by the csound program, and written to a file in the Wave (.WAV) format. If your computer has sound, and your web browser is set up in a more or less standard fashion, you can probably just click on the "results" link to play the audio file (if your mouse has more than one button, you probably want to use the left button to play). You can also download the audio file to your computer; that way you can generate a number of examples and compare them at your leisure. You can probably download the audio file by command-clicking or right-clicking on the "results" link.

The Virtual Monochord should work with with most web browsers. However, Javascript and Cascading Style Sheets (CSS) must be supported and turned on for most functions to work. Other extensions (Java, Flash, etc.) are not required.

If Javascript is on and you have trouble using the site with your web browser, or if you do not have access to a web browser with support for Javascript, please contact me at the address at the bottom of this page.

Please note that there are known problems with Netscape 4 and Javascript/CSS, particularly on the Macintosh. However, the Virtual Monochord should work well enough with this version.

If you have further questions, problems, comments, or ideas for features, or just want to talk about unusual musics, places, or activities, then please send me email at <bossert@suddensound.com>.