So a friend of mine once told me that, in 1992, SCV played this ";exercise,"; for lack of a better term, where the center snare drummer (Walter Powell) would play alternating single strokes at a tempo that he picked and change the tempo at will. Kind of like the end of the 1991 show, but unwritten and inspecifically metered. I [i]think[/i] they called it Henry's Driveway, but I might be mixing up the name of another exercise with this one, if this one ever actually happened.

If it did, has anyone seen video of it?

It may have simply been ";24"; performed as an accell. That's a guess....but it seems logical.