Below is a screenshot of Facebook testing new listen buttons in the news ticker alongside music apps like Spotify. Visually, its a bold move because they are all over the feed... and it turns a good percentage of Facebook into a music network (people, songs, apps, trends, etc).
It's also a bold move because it's potentially a very slippery slope... are "read" icons coming? "Shop"? etc? Visually that could create significant clutter / confusion - but it also creates hubs of verticalized activity. Fascinating to watch.
without the new listen buttons