Quasi R'n'B stylings like Houston and Carrie (sp?) et al.

Reducing every song or tune to the same style. I once sat through a whole evening of a popular DJ who also did the "folksinger" act. He didn't do James Taylor well at all but he tried to make everything sound like JT anyway, including Proud Mary. God, it was lousy.

"This is from our soon to be released CD..." Oh yeah, right.

Prima donna singers who don't acknowledge the band, help carry gear, thank the band, introduce them on stage, contribute to marketing etc etc etc.

Employers who short the payment for any excuse whatsoever.

Drug use by band members at any time even remotely close to performance. This has ruined many a gig for me over the years, either directly, or because the expectation of problems created anxiety in others which affected their performance too.

Anyone who dares to touch an instrument without the owner's permission at that particular instance. "He lets me play it all the time." When you're pissed?

"This guitar (or whatever) is so good I only have to tune when I restring." My ass.

Bad attempts at duplicating note for note a recorded version of anything. I'd rather hear a bad attempt at an original (and tasteful) version of anything.

Mooh.