(There's no video for Open Music System 2.3.8 (OMS) yet. Please contribute to MR and add a video now!)
Back in the day it was the most used Midi configuration application. It´s the bridge between your midi hardware and you mac.Many midi applications need OMS to work.
Install_OMS_2_3_8.sit (2.5 MiB / 2.62 MB)
System 7.0 - 7.6 - Mac OS 9 / compressed w/ Stuffit
opcodeopenmusic.hqx (3.43 MiB / 3.6 MB)
System 7.0 - 7.6 - Mac OS 9 / BinHex'd, use Stuffit Expander
Emulating this? It should run fine under: Basilisk II