So Facebook released it's first batch of early results for the Open Graph integration into social music apps. While the numbers maybe positive (I pick on Spotify because they are absolutely crushing the competition in terms of numbers, probably because users are forced to login with Facebook), this is merely a quantitative result, whereas more qualitative data (meaning my opinion) would beg to differ.
Let's go back to Spotify before the conjunction with Facebook: listened to whatever you pleased (even the guilty pleasure songs, we all have them), and you shared whatever music you wanted to in playlists. It was as simple as that, choice of what you shared. Not a bound obligation to share every song you listen to. The posts on my ticker and news feed become really repetitive really fast and, let's throw it out there, listening to music is probably the most anti-social activity out there.
You want to define to the Open Graph what music you listen to in a carefully curated fashion because your personality is carefully curated. The decision to make that all Open just goes against a psychological instinct, a subconcious OCD, to make yourself look better on your profile. It's the same premise as how some people will delete activity signatures off their wall, or their own statuses with no likes as to come across less socially inept than they really are.
You can't open-source a personality.
Graphed Usage of the Spotify Facebook app.
Source: The Verge