From the moment Greg Kot and I launched our regular “Sound Opinions at the Movies” series  at the Music Box Theatre, we’ve never been at a loss for great rock films we’d like to show. But the movie topping the list from the start has been This Is Spinal Tap, and we’re finally showing it at a super-special free screening at Millennium Park at 6:30 p.m. tomorrow—Tuesday, July 29.

Why has it taken us so long to get around to Rob Reiner’s 1984 classic, which we both agree is the best rock movie ever because it is the truest? Well, for a while, we harbored a desire to show it in IMAX (just imagine the cucumber scene!), and then we thought of Sensurround; unfortunately, it wasn’t available in either format. Nor was Smell-O-Vision an option.

You’ve got to admit, though, that Millennium Park is a pretty good fallback.

In case you missed our chat with Reiner about the film’s 30^th anniversary, you can podcast it here. And if you still need some help getting psyched up for the fun, here is an extended deleted scene from the movie that finds Bruno Kirby channeling his limo-driver character’s hero, Frank Sinatra. In his underwear, no less.

See you at the movies!