SlackBuildsOrg/audio/sfc

sfc (midi router)

sfc (SoundFontCombi) is a midi router designed to mix the sounds of
your sound devices. Up to 8 sounds can be mixed or split. There are 6
MIDI out ports and 2 MIDI in ports. Up to six different devices can be
used to produce combinations of sounds like some synthesizers.

The connections with your devices are automated. You can load/save
your "mixes" in banks of sounds, and change them via MIDI Program
Change message or by the user interface.