@Hobo: Some songs will come over as a scratchy or bass-ey mess. And as the song plays on the other end, it'll echo back through the players' mc and hit the DM, ad infinitum. This creates an unbearably loud "whooshing" sound.
Headphone can help with this, but wearing any kind of headphones for a 5+ hour session (the norm for my group) can get very uncomfortable.
I'm having the same problem as the OP, except I'm the only player via webcam, while the rest of the group (DM included) is at the table together.