Would it be possible...

[lilmul123]

To take out the Yamaha YM2612 in the Genesis, and stick it in a keyboard to create a synthesizer using the instruments on the chip?

[Rusty Venture]

If only Yuzo would have explained how he used the chip to make his awesome music...

[TmEE]

The chip contains no instruments... you make the instrument, feed it to the chip and there's so much extra HW required so its pointless. Get a DX7, its FM chip works almost like YM2612 (but is more capable, used in a keyboard afterall)

[0x15e]

It would probably be possible, but not really worth the effort. Things like this have been done before (i.e., HardSID (http://www.hardsid.com/)), but the SID was a pretty capable and unique sounding chip to begin with. It also has to have instruments loaded, just as the YM2612 would.

The YM2612 doesn't have a particularly distinct sound, IMO, and as TmEE said, there's already a synth on the market w/ similar capabilities.