Looks like the 'some sounds are commonplace on the SNES' theory has more to do with reuse rather than anything else (which makes total sense - compare the drum tracks from Hirokazu Tanaka's Mother 2/Earthbound soundtrack with those from Snoopy Concert, which he would have worked on at around the same time, as well as many other examples specific to different composers/development houses). Even then many of the source sounds originated from machines like the M1 as ne7 mentioned (this great interview with Dave Wise features not only one of my favourite answers in any interview ever - the one where he talks about using the SPC as a kind of primitive wavetable synthesizer - but a description of his use of both the Roland MT-32 and Juno-2) .
There's some really interesting info here about the SNES that somehow hasn't popped up in any of the previous chipmusic/8bc threads on the topic! I've already downloaded that cooledit BRR converter. The only method I know for 'true' SNES music is the laborious process outlined by Alex Mauer in the aforementioned post - though programming a more accessible tool for the job would no doubt be quite an achievement, there's always been some 'market' for it. I'm sure many of the same Nintendo and/or chipmusic fans who propelled programs like LSDJ and MIDINES (ha) to fame would be interested in a SNES/SFC tool too.
