Step FX parameters.
⚠️ Tracker only supports two FX per step.
Instrument index.
0 - 47 = Sample based instruments,48 - 63 = MIDI instruments64 -66 = Synth enginesnote has value 0 - 127, but can have special values:
-1 - step is empty-2 - Step is off, fade out-3 - Step is off, cut-4 - Step is off, (default)
Represents the data structure for a single step in a track.