I've figured out how to modify some things with careers, like the rabbitholes that host them and the salaries and such, but I can't figure this out: I'd like for any instrument to work with the music career. Since Late Night came out, it's kind of bugged me that the music career still required the guitar skill and none of the other instruments were incorporated. I think I can figure out how to change the instrument from the guitar to a different instrument, but I'd like to be able to change it to ANY instrument (ideally including the violin, but that might be even more complicated), so maybe one sim advances via the piano skill and another via the drums. Is there a way to change this by modifying the career xml from the gameplaydata package?

This is actually implemented in NRaas Careers right out-of-the-box - it contains a 'Music Skill' metric override for the music career that accepts all instruments including the violin

This is the best news! Thanks!