Why do some of my Facebook friends on chat have a musical symbol by their names?

Question

I have noticed that some of my friends have this musical symbol to the right of their names in the Facebook chat panel.

What does it mean?

Answer 1

It means they are listening to music from Open Graph Facebook applications. Hover to see what they are playing and listen as well.

For more info: https://blog.facebook.com/blog.php?post=10150457932027131