The game has a lot of ways to interact with other players but there could be more, there is also a severe lack of interaction with NPCs. This is why I suggest instruments to just interact with them more.
Some instruments could be bought from different islands or all islands have the same but they cycle. They could also just be found or even fished up. They could have buff skills or just be like instruments in TWW, where you are able to play music to have fun.
It would be up to the devs if they want to have it just be set songs like in sea of thieves or you need to use keys to play the instrument. If they go with the former then having music sheets that can only be found in places such as diving spots or sealed chests would be great since some songs could be extremely rare and it would be a good way to add more things to diving spots.
This could be used to in a way where if you play songs in towns you could get donations from the townsfolk and on the ship your crew could maybe just dance around and add some more depth to them. It would also add more possible interaction with players with possible bands forming.
Sounds like a way to print money in towns, but I think a random instrument with no gameplay value would be fun, similar to the Rain Song in Terraria. There should be a 1% chance for any shark to drop a guitar that can play music, and it provides no gameplay benefits.
I guess digging is a way to print money, albeit very slowly. Maybe getting donations from instruments is fine? The difference is that shovels are mainly used for treasure charts while instruments are only useful for printing money, with the crew interaction being a secondary visual effect. If it is a very low amount of money it’s fine, but that also means that the item damn near useless.
This is brilliant suggestion like I’m sure if I will start playing music near arena(forgot island name) some randoms will join me and we will make some good(or bad) music