Listen to Music with Viewers (Prime Viewers only)
Similar to the Watch Party. This way Streamers could share music with some of the viewers (prime members) without this whole DMCA problem because only viewers who have access to the songs anyway can listen to them.
The only issue would be how you would handle that the streamer hears the music too, without making it audible for nonprime members. But this way people would still have to pay somewhere to listen to the music to give the artists credit and at the same time it would improve the quality of streams. In my opinion, this would even help musicians get more popular because I personally learned about many artists because Streamers introduced them to me.