I am trying to find a setting I found a while back. (at least I'm about 80% sure I've seen this setting) I can't remember which mod it was and I'm not seeing it anywhere now. There was something in a mod setting that discouraged sims from preforming or playing instruments at parties. I don't remember the exact wording, but that's the gist of what it did.

I know I can alter retuner settings, but really it only bugs me when everyone jumps on an instrument or whips them out at gatherings. I'd rather keep that user directed.

NRaas > SP > General Options > Options: Skills > Allow Party Instrument > T/F
(SP Skill add-on module required)