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.
Here is a small minor blues jam. I got the keyboard pattern from an old Doug MacLeod album, and it fits the original drum track quite nicely.
It's basically a Cm blues, with a twist on a V, as it goes up a semitone to Ab7, then back down to G. I usually alter the last G, either as a G13b, or G9+.