Rich Music Format
Rich Music Format is a proprietary audio file format designed by Beatnik, Inc. to allow simultaneous playback of MIDI and digitized audio. The format has never been properly documented and, while Beatnik did release a datasheet and whitepaper with some details on the format, their website appears to be down and the Archive.org grab does not seem to have successfully preserved them.
- . Latest Wayback Machine capture of beatnik.com, in case anyone wants to try and grab those PDFs.
- RMF - Rich Music Format on music-notation.info.