Neither the CMS or Adlib music chips require an IRQ, only the digital and midi interface capabilities of the Sound Blaster do.
Many more games support Adlib than CMS music. In games that support both, CMS support is usually an afterthought.
You have a rare board in that SB 2.0, few were ever upgraded with the CMS chips and the upgrade requires a custom PAL chip to work.
I bought this SB2.0 boxed some months ago on Ebay but didn't start using it until recently when I built a 386 gaming rig...back then I didn't know about these CMS chips so it was kind of a suprise too see them on the card
