I can watch and hear others just fine, but when I try to play a video others can see and hear it but I can't?

Are you on standalone?

My music doesn't work at all.

http://atelier801.com//topic?f=6&t=818749&p=1
http://atelier801.com//topic?f=6&t=818635&p=1

Try to switch to browser.

Browsers such as Firefox and SeaMonkey do not support html5 video and audio
Try something else

Are you in a tribe? If so, you have to get to the rank that you can play music, or it could be a bug, or your browser is not compatible with it, or your browser never support html5 videos and audio.

I'm sure she's talking about MUSIC rooms not tribe house xD
If it's your music you can't hear, maybe as other ppl have said, switch the browser. I always use the E thing whatever it's called