Help: Add or replace music/songs played on instruments

I've opened this query in this section as I believe it to be most appropriatre; apologies if this is not the case.

I'm trying to find out whether there's a way to add (or replace) the music and songs played by a sim on their instruments (piano, violin, guitar etc). What is there is very nice, but it would be awesome if I could add, for instance, some Chopin pieces for the sim playing the piano, or some Spanish classical on the guitar.

Would really appreciate any assistance on this point :)

TIA.