History. Your expertise aids you in recalling lore related to your instrument.
Performance. Your ability to put on a good show is improved when you incorporate an instrument into your act.
Compose a Tune. As part of a long rest, you can compose a new tune and lyrics for your instrument. You might use this ability to impress a noble or spread scandalous rumors with a catchy tune.
Additional uses. You can use your musical instruments to do a variety of things, as your DM if you may use the tools for a specific task. Examples of such tasks are as follows; Indentify a tune, improvise a tune.