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.
Just my take on this cool, simple, but "naked' track. By naked I mean there's lots of space...and my instincts when I'm playing tell me to fill up the space. So it took me a couple of tries to dial it back a bit