Ardour

MIDI IN

1. Add plugdata as an instrument to an empty MIDI track.
2. In plugdata, use one of the MIDI IN objects and route MIDI data from it (see example).
3. Play notes on this MIDI track using any usual method — keyboard, piano roll, etc.

MIDI OUT

1. Add plugdata as an instrument to an empty MIDI track.
2. In the Editor Mixer (Shift-E to toggle) for the plugdata track, add an instrument which will receive MIDI data, right below the plugdata plugin (a).
3. In plugdata plugin, use one of the objects that sends out MIDI data (see examples).

FX

1. Add plugdata-fx as an effect device to an audio or MIDI track.
2. In plugdata, use [adc~] object to receive audio from your DAW (see examples).