I bought this scrumptuously wicked soundtrack at Amoeba Records on Sunset Boulevard around Christmas time in 2005.
The premise of the film is pure genius. Get this, a group of bikers learns the secret of returning from death, makes a pact, commits suicide, and sure enough, return to wreak havoc as the undead!
The music, composed by John Cameron, and played by the band Frog, is haunting, moody, funky, stark, with an acid-drenched wah wah. There is a hippie-ish folk ballad a la The Wicker Man, and there is even a recurring theme that rocks! It would find a home in any biker movie(Rebel Rousers, Wild Angels, you name it), let alone one that features zombies!
Far out and...you said it...groovy!
Check it out