By Steve Simels
Updated January 13, 1995 at 05:00 AM EST

Less, the sages say, is often more, but that may not be the case with this new version of This is Spinal Tap, the funniest rock film ever. Here, along with picture and sound quality far superior to any previous Tap video incarnation, we also get two running commentaries (director Rob Reiner on one audio channel, the principals on the other), a 20-minute demo reel, and more than an hour of outtakes (including Bruno Kirby singing Sinatra songs in his underwear). Much of this is amusing, but whether we really need these extras is arguable; in fact, as Reiner himself notes at the outset, they’re a bit like a magician telling you how he did a trick. A-