Facebook has rollout a new “listen with” feature which allows users to enjoy the same song with your friend via the site at the same time. This is not like sharing but actually sharing the same song and listening to it at the same time.
This cool new feature will be rolled out in few days for all users. You can watch out a friend who is online and listening to a song, you can see a music icon next to their profile photo.
You can just become DJ between your friends, you can chat and discuss the song as it plays for everyone online.
I assume, Facebook will be working on similar feature for videos very soon, where we can watch a movie with our dear friends at a time