The #NowPlaying pane gets to the heart of what’s really wrong with the app and, may I suggest, Twitter circa 2013. In order for this 25% of the app to be useful, the people I trust and follow must also auto-tweet what they’re listening to, complete with hashtag detritus (or trolls). Perhaps I’m just too far past what Twitter considers cool, but a stream littered with #NowPlaying refuse (or Vines or Foursqure check-ins, for that matter) is a sign that I need to spend some quality time with the unfollow button. Twitter has built an app that requires users to abuse their timelines and followers with machine tags without any meaningful way of tuning out that noise.
I use Rdio and I think they’ve got social done pretty well — it’s external to existing social networks but easily connects to them, so I can choose to engage with it when I want and otherwise keep it out of the way. (So it’s interesting/odd that Rdio now also hooks to Twitter Music.)