My Cloud Ex2

I have a Mac and Sonos sound system. Is it possible and easy to set up a My Cloud device two bay with one disc used for the storage of my music collection and the other disc to back up Mac using time machine

Not sure what your question is. But if you are asking about a My Cloud EX2 device, see the dedicated subforum for the My Cloud EX2. This subforum (My Cloud) is generally for the single bay My Cloud units which are different than the EX2 series.