except those pocket operators. Those are pretty affordable music thing. Its basically a circuit board, even the hanging part is part of the board.

https://teenage.engineering/products/po

They're lots of fun. (I have the rythmn and robot ones). Its weird you could do this on a cell phone now, but the separate device kinda works well.

of course the optional case is about half the cost of the device.. but I never bought one and haven't had a problem.. and runs on regular aaa batteries!