I don't think he meant vgm dumping, I think he might have meant ripping, there are several games that are not possible to Dump due to the lack of a sound test and unavoidable sound effects IE: Paperboy. I have tried using a HEX Editor to locate the music code and use some software like audacity that support some Genesis sound drivers, but lack of knowledge and lack of markers in the hex made it impossible.
I am curious if anyone ever tried to do some ripping, there are no guide I know of sadly on how to do it.