@blueveinedthrobber,
Who were you doing this favor for? A friend? A relative? A politician who knows your dirty secrets? A homeless man on the street?
Did you have to bring in your own equipment and music? Set up without any help?
As for the no dancing? That's fine by itself. That's more on the groups fault. A hive mindset of wallflowers. Perhaps they shouldn't have even thought about bringing in a DJ if they weren't a dancing crowd.
Whoever it was, if I was you, I'd confront them on these big details. This person who received your favor needs to be shamed. What a jerk.