The 7-string guitar is not something you can just pick up and play, for several reasons, the main one being that your brain is wired for the 6-string, so looking at the guitar makes the 7th into the 6th, etc. However, a couple of weeks of playing and practicing in the dark solves that problem. I had one quick lesson with Bucky Pizzarelli many years ago, and have favored the 7-string ever since, even for 6-string work. It's also a lot easier to deal with if you have some classical or finger-style technique.

One of my most interesting early experiences was playing a wedding with a standard-issue "society band". The leader offered me extra scratch to play solo on the breaks, maybe 3 20-minute sets. Turns out all the older folks at the party were much happier to dance to my song selections than the band's, and I filled the dance floor with nice, easy versions of Misty and Satin Doll and Time After Time, etc., with the bass lines making a nice danceable rhythm. When the band returned, the kids got to dance to the latest pop hits while the adults remained seated. Great lesson is the importance of songs rather than rhythms in getting people onto the dance floor. Added fun in pissing off the bandleader, too.