I engage them all. So I’m charging more for the extra demand on me. I usually have to take a break after a group (not that I’ve done a group in a while) so I wan’t to be compensated for that, plus they are effectively getting multiple lessons at a discount. I actually tend to advise people not to have group sessions, as singing is such a personal thing. Whereas if someone wants family sitting in on a session, then great so long as they aren’t disruptive.