I'm pretty lucky - I always had good drummers. But the best guy...it was like magic. We were taking a break during our first practice together, and the singer and guitar player made a soda run. We hung around and schemed. I thought it would be funny if we would "bump" the groove over by 1/2 beat (like Tower of Power occasionally did/does) without telling the other two. I knew I had the right drummer when he knew what I was talking about! We decided to pull our gag during the guitar solo in Led Zep's "Rock and Roll," the first song we were going to do after the break.
Song starts, we're laying the beat down hard, and here comes the solo. We look at each other and nod...and BUMP! I doubt the guitar player even heard me, but pushing the snare to the "and" of 2 and 4 was enough. It was like someone turned gravity off. He looks around at everybody, his foot tapping starts to slip, he fumbles through another measure or two, and finally grinds to a halt. The drummer and I laughed our a$$es off! Pretty good for a first practice. We promised never to do it again without asking.