A chromagram, measuring the energy at particular chroma within an nTET tuning system.
Possible extension: TODO: Could have arbitrary tuning systems if precalculated the exact fft bin + interpolation data.
input fft chain, that is, from an FFT UGen
FFT size, required for initialisation
Equal divisions of an octave, e.g. n=12 is 12TET, 12 steps in an octave
Base frequency or tuning; will correspong to index 0 in results (conventionally, this would be a 'C' in 12TET, but its an arbitrary reference)
Number of octaves considered from tuning base up
Whether to integrate from frame to frame, off by default
Coefficient of integration
Default of 2 is a 'normal' octave; other ratios are possible, e.g. Bohlen-Pierce scale uses 13 equal divisions over the ratio of 3 for a 'tritave'
Defaults to off, but if set to 1 will normalize each frame with respect to itself (as long as there is non-negligible power), potentially providing a more robust measure for comparison between frames (each frame will have then a normalized distribution over chroma, independent of volume)