Easily the BEST guitar movie ever.
It's available as an NTSC, region 1 DVD from Amazon. There is no PAL, region2 or 0 available.
Blues guitar by Ry Cooder
Classical guitar by William Kannengeiser
Rock Guitar - by Steve Vai
Arlen Roth tutored Ralph to do the miming
"Eugene's Trick Bag" (the neoclassical bit that wins) is played by Vai. A large part of it based on Paganini's 6th Caprice. I have the "Trick Bag" tab if anyone's interested. It can't be played easily on a normal Tele as it uses the 22nd fret quite a bit, although you need a Tele to "fret" the highest note of the final cadence on the neck pickup.
Vai got the job after the director heard The Attitude Song
The director said he had to get Vai to tone down his performance to make it more believable that he lost the duel - If you've seen the Eat 'em and Smile
tour footage (with Dave Lee Roth and Billy Sheehan), you'll understand why. Those days, Vai was doing things like playing the solo for Goin' Crazy
left handed, doing the Michael Angelo "tapping on two guitars simultaneously", playing the bottom of the bass while billy played the bottom of the guitar and vice-versa -all while doing assorted gymnastic jumps, running around and sliding across the stage.