Hi,
The chat system is what you need indeed, so keep studying that until you fully understand the difference between this example and your scene.
typically, instead of sending a chat, you will send a string reference of the music, and instead of showing that string in a textfield, you will find the related music and play it.
One other way tho is to have a prefab acting as the music player, and simply spawn that as if it was a player, only it's just a "music player" ( no pun intended ( no PUN intended)!!
you can maintain player properties, so you could reference the music you want to play as a property of that player, OR have a prefab for each music you want to play and spawn the one you need, without further worrying about communication.
Does that make sense?
bye,
Jean