I just played one this past weekend at a private club that I regularly play.
I've gigged with the other guitar player and drummer for the last few years with other spots being filled as needed. This gig was quite a surprise. A keyboard player that had just gotten off the road after over a decade of touring showed up. He just moved to town a couple months ago and boy can he play. Unfortunately, the thing about bands is the chemistry both musically and personality wise need to be there for a long lasting working relationship to work. In this case it doesn't exist with the other fill in players.
From my experience I will never suffer again having someone in the band who doesn't fit in just for the sake of having the spot filled. If the personality fits then I'm 100% in. If there is instability and strangeness to a degree that harmony is missing then I'll keep looking for that "right" person. It's kind of like a marriage, right?
"No Tele For you." - The Tele Nazi
Ha! Tele-ish now inbound.