Waiting for Guffman is Christopher Guest's mockumentary sendup of community theater. It's a helluva lot of fun and at two bucks it's probably cheaper than a rental. Guffman is, however, a well-known, well-liked film, and as such doesn't need a lengthy writeup (besides, you can find several here).
Lisztomania, on the other hand, is one of those forgotten uh, gems that nobody appears to have seen (though your parents might remember the title). It was director Ken Russell's 1975 followup to the better-known, better-liked Tommy, and stars The Who's Roger Daltrey as a heavily fictionalized version of the world's first musical superstar, Franz Liszt. The film follows Liszt's career, from his zealous womanizing to his associations with fellow composers Berlioz, Mendelsohn, Rossini, and Chopin.
That's about where the history stops. Richard Wagner is a vampire who wants to purify the Aryan race, and he's built a Frankensteinian superman (based on Nietzsche's Superman, as long as I'm dropping names) with the face of Adolph Hitler to help him accomplish his goal. Wielding a guitar that fires like an uzi, the monster lumbers across Europe, destroying everything in its path.
I'm not making any of that up.
I'm also not making up Ringo Starr's brief appearance as the Pope (complete with flashing lights and sirens), or Rick Wakeman's performance as Wagner's monster. Wakeman scored the prog rock/classical soundtrack, and it was on this strength that I made several unsuccessful attempts to get evil_jim and the_tick27 -- both Rick Wakeman fans -- to watch the film. Ah, well. Anyway, it's a musical, and a damned weird one, especially since you can tell that the culprits have approached making it purely with their own agenda, throwing history, along with music appreciation and film theory, out the window.
Is it a good movie? Well... no. Roger Ebert gave Lisztomania three stars, but it isn't out on DVD and the reasons will be immediately apparent. It holds the same grim fascination as a car wreck or (more appropriately) a mime crushed by a fallen grand piano. How did they get the funding? How did they entice the involvement of big-name, semi-respectable stars? Did nobody have the presence of mind to say "Wait a minute, do we really want our names attached to a musical which features women tap-dancing on a 20-foot penis as it is led to the guillotine?" I'm not making that up, either.
In the early '80s, Frank Zappa released a song called Cocaine Decisions which was about the unjustifiably stupid things that get greenlighted by the entertainment industry. Lisztomania is probably what he was talking about.