Yes, the strict-tempo guys can be a hoot. I was in one dance band and we had this gig for a serious ballroom dancing club (like, the real real thing including the ladies in the fancy outfits, and the deal where doing the Latin styles they whip their heads from side to side, etc.) - and after about two numbers this little old man came up to the bandstand, mad as hell because we were not playing dance styles at their EXACT specified tempos (I mean, if the US Ballroom Dance Association or whoever says a waltz is 126, it damn well better fall between 125 and 127!). After that the bandleader always had a list of MM markings and a metronome on the stand for those kinds of gigs. I don't know how we got through that first one - I think the drummer had an electronic nome (not common in those days) and the leader had him click off each tune.