aplaymidi -p client:port[,...] [-d delay] midifile ...
aplaymidi is a command-line utility that plays the specified MIDI file(s) to one or more ALSA sequencer ports.
A client can be specified by its number, its name, or a prefix of its name. A port is specified by its number; for port 0 of a client, the ":0" part of the port specification can be omitted.
Multiple ports can be specified to allow playback of MIDI file(s) that contain events for multiple devices (ports), as specified by "Port Number" meta events.
For compatibility with pmidi(1), the port specification is taken from the ALSA_OUTPUT_PORTS environment variable if none is given on the command line.
aplaymidi handles "Port Number" meta events, but not "Port Name" meta events.
Clemens Ladisch <firstname.lastname@example.org>