Some features are disabled in mute-mode to make sure you will not accidently save, download or comment on a different jamtrack from the one you are currently hearing. You may either lift the mute-mode to download or interact with the currently displayed remix, or move to the currently playing track with the green GOTO button.
I've added to a lot of the wonderful jams that others have uploaded, but haven't started many myself, so here's a little thing I threw together to see what the incredible talent here on wikiloops can come up with. It's a bit rough, but I hope it's workable. :)