The argument is a tab representing a midi message, see function @midi_read. The @midi_getChannel extracts from this tab the channel of the message if the message corresponds to a channel specific command (i.e., noteOn, noteOff, Aftertouch, Controller, PatchChange, Pressure and Pitchbend, see @midi_read).

On a non-channel specific command, the result is undeterminate.

See also Handling Midi @hz2midi    @hz2midicent    @hz2symb    @midi_getChannel    @midi_getCommandByte    @midi_getCommand    @midi_getMetaType    @midi_isAftertouch    @midi_isController    @midi_isEndOfTrack    @midi_isMeta    @midi_isNoteOff    @midi_isNoteOn    @midi_isNote    @midi_isPatchChange    @midi_isPitchbend    @midi_isPressure    @midi_isTempo    @midi_read    @midi_track2ascii    @midi2hz    @midicent2hz    @symb2midicent