--Tim Tully (with his friends) is the primary composer for MM3~5 and Planet's Edge. (see below for what equipment he used)
--George Sanger did ONLY the introduction theme for MM3 and Planet's Edge.
--Rob Wallace maybe did one track for MM3 and 50% of the tracks for Planet's Edge (music which should have been for the Genesis version of King's Bounty). There are no records yet of his commissions.
--Takeshi Abo did a few tracks in MM5, which were apparently for MT-32.
The original Might and Magic III comission from New World Computing to Tim Tully states:
"Each work of music shall consist of a maximum of eight, monophonic tracks, each usable by one of the instrumental timbres found in the Roland MT-32 synthesizer."
The original Might and Magic IV comission states:
"Standard MIDI Files, voiced for the Roland MT-32 synthesizer. The MIDI files will consist of no more than eight tracks apiece. Each track will be monophonic, such that no more than one note plays at any one time."
In Tim's letter to Jon van Caneghem (1992-03-06) regarding Might and Magic IV, Tim states:
"I've begun on a theme for Xeen, having gotten a blow-by-blow of the opening from Mark [Caldwell]. I hope to have something solid this week. I'll do this piece for a full-bore (shudder) MT32 as we discussed. "
Might and Magic V commission (November 1992)
"Standard MIDI Files, voiced for the Roland MT-32 synthesizer... . The MIDI files will consist of no more than eight tracks apiece. Each track will be monophonic, such that no more than one note plays at any one time. ... (Also) will produce any number of these pieces more fully, specifically to take full advantage of the capabilities of the Roland SCC-1 Sound Card."
NOTE: Only the introduction theme for MM4 & MM5 have unique Canvas versions composed directly by Tim. All of the other Canvas versions were made by the sound programmer(s) from Tim's original versions by simply patching in alternate instruments.
However, after Might and Magic III & Planet's Edge were finished (but before working on MM4&5), Tim Tully sent a demo tape to other companies to get work. In an accompanying letter Tim writes:
"Bear in mind that these were specifically produced to accommodate eight monophonic tracks, per the client’s understanding of the hardware in his installed base. All the tunes on the tape are played on a CM-32L."
There is also a note in 1992-07-06 of Tim shipping "Sound Canvas to NWC". There is no model mentioned.
So Tim composed the music either on an MT-32 of a CM-32L. But maybe the instrument is actually an CM-32L. But because the patches were the same, it probably was not important.
In the final version of Might and Magic 3, the "temple" theme does have the "chime" instrument that is only in the CM-32L. However, in the original version of "temple" sent by Tim to NWC, the "chime" instrument is not present. This leads me to believe that someone else on the design team added it. So this doesn't narrow it down.
In one of the original midi files for one of the Might and Magic 5 tracks, there is channel for "horses" -- which must be the CM-32L horse sound effect. However, this channel is entirely blank. However, this leads me to wonder if Tim had CM-32L, but deleted the horse channel (perhaps because that sound is not on an MT-32).
When George Sanger was commissioned for MM3 & PE, it states:
"We need a one (1) minute theme that will be orchestrated for use with the ADLIB and LAPC-1 boards."
I know for certain that George had an MT-32. I don't know about anything else. The midi file itself is configured for MT-32/CM-32L patches. Since both are basically the same sound (except for some extra instruments) it's difficult to know. No instruments are included that are unique to the CM-32L.