My big beef with my band. Waiting for the guitarist to tune up, find his plectrum etc, waiting while the drummer drinks his pint or searches for his sticks on the floor (get a stick bag fer cryin out loud).
I'm a big fan of 3 songs back to back, pause for 'hello and we are' type chat then straight in with the next 3 songs. My bandmates don't get it, so I've given up. I once went to see Gladys Knight and the Pips and THAT was a proper performance with everything to time and script and no gaps between songs unless they were planned and even then there was some background music being played. I suppose some might say that it's too slick, but I loved it.
There's a pretty good local folk singer I know who rambles on about the back story of each song for a good five minutes before playing it, but I guess that's part of the folk genre