There’s a reason we still talk about ‘This Is Spinal Tap’ after all these years. Not only is the movie screamingly funny, but it’s still the most accurate movie about rock 'n' roll ever made. In fact, a lot of musicians will tell you it’s too close to home, and the first time many of them saw it, they weren’t laughing.

This year marks the 30th anniversary of ‘Tap,’ and you can celebrate the brilliance of the film with an iPad movie app featuring 'The Special Features Version,’ which includes many great extras, likes new interviews with director Rob Reiner and cast members, plus commentary by more than 40 musicians who recall their own Spinal Tap-esque experiences.

And you can celebrate April Fool's Day with Tap, since that cool interactive app is available for free today.

Even if you think you know everything about the making of ‘Spinal Tap,’ YEAH!'s features-stuffed app reveals even more, including how the '70s ‘Midnight Special’ TV show was the initial inspiration for the movie, how fans at a screening didn’t realize Spinal Tap weren't a real band, how Black Sabbath almost sued over the infamous Stonehenge segment, and much more.

It really is indeed remarkable that ‘This Is Spinal Tap’ is still around and revered after all this time, but again, it was absolutely right on target, and as Harry Shearer, a.k.a. Derek Smalls, once told Mojo, “The closer we got to the real thing, the closer the real thing dared to get to us. Reality was calling our bluff at every step.”