The Cleveland Symphony Orchestra was rehearsing Beethoven's Ninth Symphony. There is an extensive section where the bass players don't play for twenty minutes of so. One of them decided that, rather than stand around on stage looking bored and stupid, they'd all just file offstage during their tacit-time and hang out backstage, then return when they were about to play. It seemed like a good idea at the time.
On the night of the performance, the bass players filed off as planned. The last one had barely left the stage when the leader suggested, "Hey we've got twenty minutes, let's fun across the street to the bar for a few!"
This idea was met with great approval, so off they went, tuxedos and all, to loosen up. Fifteen minutes and a few rounds later, one of the bass players said, "Shouldn't we be heading back? It's almost time."
But the leader announced, "Oh don't worry, we'll have some extra time - I played a little joke on the conductor. Before the performance started, I tied string around each page of his score so that he'd have to untie each page to turn it. The piece will drag on a bit. We've got time for another round!"
So another round they did, and finally - sloshed and staggering - they made their way back across the street to finish Ludwig's 9th.
Upon entering the stage, they immediately noticed the conductor's haggard, drawn and livid expression.
"Gee," one player queried, "Why do you suppose he looks so tense?"
"You'd be tense, too," laughed the leader. "It's the bottom of the ninth, the score is tied and the basses are loaded."