float2tune()

Category

Math / Pitch quantization

Description

Converts a control value to an equal-tempered pitch multiplier, quantized to whole semitones. The function reads a new value only at the interval set by retrigger_samples and holds the previous multiplier between updates. Internally it uses the semitone index int(value*12) and returns 2^(semitone/12).

Arguments

• value: pitch control value. Values from 0 to 1 select fixed notes from unison to one octave up; values from -1 to 0 select notes from one octave down to unison. Values outside this range can select wider intervals.
• retrigger_samples: number of samples between value updates in Syntropy's 44.1 kHz reference-time domain. It is adjusted internally for the host sample rate and oversampling. Values below 1 are treated as 1.

Example

0.55*release(30000)*saw(X*float2tune(2*rnd()-1,11025))

Notes

Use float2tune() to turn a changing or random control signal into stable musical note ratios without recalculating pitch every sample. Each occurrence in a formula has independent held state; up to 16 occurrences are supported per voice. Abrupt semitone changes can still click when used directly at audio rate, so use a musical update interval or place the result in a suitably enveloped sound.

Available since Syntropy version 2.4.