Rock 'n' roll movies are a mixed bag, to say the least. They range from the genius (Stop Making Sense) to the good (The Last Waltz), the dated but watchable (Monterey Pop), the contrived but watchable (The Girl Can't Help It), the noble failure (U2's Rattle & Hum), the ignoble failure (Tommy) and the truly execrable (Sgt. Pepper's Lonely Hearts Club Band).

Only a select few are true classics. A Hard Day's Night is one of them. In fact, I would go so far as to say that it is the classic rock movie.

Not only did it cement the Beatles' worldwide fame, it redefined for an entire generation what rock 'n' roll was -- personified in four young men from Liverpool, who raised the bar for everyone that followed them.

A big reason the film does this so well is that it presents the Beatles as stars, rather than relegating them to walk-on performances, as happened with so many other rock acts. Nor does it force the Beatles into roles they were unprepared or unable to play, as Elvis Presley's movies did. Instead, the film presents us with a slightly fictionalized, somewhat surreal version of a typical Beatles day. We see them running from train to hotel, press reception to performance, evading rabid fans, playing their songs, dealing with neurotic managers and TV producers and trying desperately in the middle of it all to get some time to themselves. The essential theme is that of youth trying to get out from under the constraining thumb of authority -- and if someone can come up with a better description of rock 'n' roll, I'd like to hear it.

Many elements contribute to making this a classic film. One of them is the director, Richard Lester. A film like this requires a sure hand behind the camera, and Lester has it. He never neglects the quality of the music for the sake of comedy, or vice versa, and finding excellent visuals at every turn. He has great comic timing, and knows just how long to hold a reaction shot, just when to cut to a close-up, just where to position his camera to bring out the best in a scene.

Another factor is the man who wrote those scenes, Welsh playwright Alun Owen, who does a masterful job all around. He observed the Beatles in action before and while writing the screenplay, and he really captures their personas in his dialogue. His scenes highlight the Beatles as a group, and more importantly as individuals. Perhaps the best example of how he does the latter is the "shirts" scene with George Harrison. Corralled into a meeting with an overbearing teen-TV producer, Harrison is unfailingly polite, even as his laconic remarks become more and more scathing.

The film is loaded end to end with great scenes: there's the opening dialogue on the train ("Who's that little ol' man?"); the hilarious confrontation with the stuffed shirt ("I fought in the war for your sort!" "I'll bet you're sorry you won!"); the delirious backstage confessional between Lennon and the dowager who thinks John is ... him; the great "he's very clean" running gag; and the antic lunacy of the makeup room scene, which parodies Shakespeare, television, the Queen, the Beatles and the movie itself, all in about five minutes. And those are just the scenes that feature the Beatles -- there are several hysterical scenes focusing on secondary characters.

Which leads to another factor: the supporting cast. From Norman Rossington as the lads' hapless road manager to John Junkin as well-meaning but dim roadie Shake to the delightful Wilfrid Brambell as Paul's grandfather (probably the best performance in the film) to Victor Spinetti as the harried TV producer, there's not a bad performance in the film. For all that it focuses on the Beatles, this is at heart an ensemble film. The supporting roles are just as important as the leads, are written that way and are played that way. Part of this was calculation on producer Walter Shenson's part; he shrewdly cast veterans in the rest of the film in case the Beatles proved to be bad actors.

But Shenson needn't have worried. His stars were naturals, equal to the task. Of course, they get a break in that all they have to do is be themselves. Doing that, though, is not an easy job when handling scripted dialogue -- especially if you're bandying psychological jargon about, as Ringo and George do in a great early scene. But the Beatles handle their lines well, John and Ringo especially, and they have undeniable charisma.

Part of this is due to where the group was in its career at that time. The Beatles then were four young, energetic men, just coming to realize they had the world by the tail, and the movie overflows with that confident, cocksure attitude. Whether they're cracking wise or playing their songs, it's difficult to take your eyes off them even today.

And that leads to the final and most vital component: the music. The songs here represent some of the Beatles' best early songs: "Can't Buy Me Love," "And I Love Her," "I Only Want to Dance With You," "I Should Have Known Better," "If I Fell" and the classic title song. They add a lot to the movie's already considerable bounce and energy, and the Beatles perform them with elan.

This movie is like the Beatles themselves -- energetic, joyous, infectious and above all fun to watch. It leaves you smiling, singing along and wanting to see it again ... and if that isn't a classic movie, I don't know what is.