No music for GM

I'm having a problem with the jukebox that doesn't seem to be the same problem others are having. I'm not able to hear music as the GM when in a game. I can hear the music fine when it's just me, but when playing a game, I hit the button to play the nice mood music I've queued up, and I don't hear anything. I ask the players, and they are all hearing it fine. This has happened on two consecutive sessions. I usually have 3-6 players on at a time (including myself), if that makes any difference. I'm running Firefox 38.0.5 on Mac OS 10.7.5

Have you checked your master volume in the settings tab?

Yes, it was all the way up.

Ok, guess it's time to get the baseline going: Can you please follow Steps 1-3 of our Solving Technical Issues wiki page, taking special care to temporarily disable all browser add-ons and extensions, temporarily pause your anti-virus, and try switching browsers (for Chrome/Firefox specific issues) to see if one of those components is causing the problem. If all of that fails, please follow Step 4 , including providing all of the necessary information, so that we can further assist you. Also, are you using the built in video chat, or something external?

I'll go through the steps, but to answer the last question, I'm using a Google hangout in a separate browser (Chrome) for audio/video chat (although we were just using it for audio when I had this issue), and running Roll 20 in Firefox.

Ok, 1-3 is done and all appears to be in compliance. However, the problem only occurs in-game - when I'm on by myself, the music plays just fine. I guess I'll see what happens in our next session.