Pitch Following

Use these settings when pitched events are matched too narrowly or too loosely, or when the score needs a different tuning or transposition. OpenScofo compares the audio spectrum with harmonic pitch templates.

Options

Keyword	Default	Accepted value	Effect
`TUNINGA4`	`440` Hz	Positive number	Reference frequency for converting subsequent written pitches to Hz.
`TRANSPOSE`	`0`	Number of semitones	Adds a semitone offset to subsequent named pitches. Values outside `-36` to `36` produce a warning but are still stored.
`PITCHTEMPLATESIGMA`	`0.5`	`0` to `1`, inclusive	Width of the harmonic peaks, expressed on a semitone scale. Larger values broaden the pitch template.
`PITCHTEMPLATEHARMONICS`	`10`	Positive integer	Maximum number of harmonics used to build each pitch template, including the fundamental.

Tuning and transposition are applied while reading pitches. Set them before the affected events. Pitch-template settings are global, so keep them at the beginning of the score.

The actual template width has a minimum determined by FFT bin spacing: PITCHTEMPLATESIGMA 0 does not create a zero-width template. Harmonics above Nyquist or with negligible weight are omitted, so the harmonic count is an upper limit.

Practical start

Confirm TUNINGA4 and TRANSPOSE first. If expressive intonation or wide vibrato causes missed notes, test a slightly larger sigma. A wider template can also make neighboring pitches harder to distinguish. Compare the same passage before and after each change.

BPM 72
TUNINGA4 442
TRANSPOSE -12
PITCHTEMPLATESIGMA 0.8
PITCHTEMPLATEHARMONICS 8

NOTE C5 1
NOTE D5 1

Here the named notes are followed one octave below their written pitches, using A4 = 442 Hz.

YIN pitch estimation and spectral rolloff are separate descriptor settings. They do not set the width of the follower's harmonic pitch templates. For analysis window and update sizes, see Audio analysis.