1:(1+1.618):(1 + 2 x 1.618):... :(1-1.618):(1 - 2 x 1.618):...and are synthesized using FM with a 1:1.618 carrier to modulator ratio.

The patch plays six voices of FM. There are four controls which are global, i.e., shared by all six voices. These are seen in the first event of the qlist:

base-freq 1000; octave 1.618; steps-per-octave 9; fm-ratio 1.618;

The "base frequency" is the frequency in Hertz of the "reference pitch" in the scale; in the usual Western scale this is 440 corresponding to A above middle C but in Chowning's it is set to 1000. "Octave" specifies the ratio of two notes an octave apart (usually 2; 1.618 in this piece); "steps-per-octave" is normally 12 and is 9 here; and "fm-ratio" is the modulator-to-carrier-frequency ratio, which you can set to one, for instance, for a "harmonic" sound and which Chowning sets to 1.618 again. The messages for the Western ("bach") tuning and the Chowning tuning are pictured below.

The six voices have controllable amplitudes, carrier frequencies, indices of modulation, and depth and speed of "beats" in the modulating oscillator. The first event after startup in the qlist, for example, sets these five for voice one out of the six:

amp1 80 5000; index1 20; pitch1 18; depth1 22; speed1 4;

Voice one at the first event

Here "amp" is the amplitude in dB (with 100 being the maximum amplitude); as in the Stockhausen patch you may specify a fadein time, which is 5 seconds in this example. "Index1" gives the modulation index in hundredths; "pitch1" gives the pitch in steps above or below the reference frequency (in this example it is two octaves, 18 half steps, above; negative numbers specify steps below.) You may specify decimal fractions of steps if you like.

The "depth1" and "speed1" are the depth of beating in percent and the beat speed in tenths of a Hertz. Tbe beating actually causes the modulation index to rise and fall periodically.