External Music Service, Audio Sync Plugin
Create a plugin, that will allow a user hear the music the streamer is playing via their own Service, Spotify/YouTube/Amazon/Bandcamp etc
(linking a currently playing song to a database on each service)
so that the viewer is hearing music through a license they already paid for, and the streamer won't get in trouble for playing infringing music. and if a user doesn't have a paid service linked, use that spot to advertise a service such as amazon music.