"Rust Never Sleeps," a film fantasy of an idealized rock concert now playing at the Key in Georgetown and College Park, has more than meets the eye. Some of its best parts are directed at the ear, others apparently at the collective musical unconscious that awakened in the '60s and is now beginning to meditate on its mortality:

"The king is gone but he's not forgotten/This is the story of Johnny Rotten/It's better to burn out than it is to rust/The king is gone but he's not forgotten."

Neil Young, who with his group Crazy Horse performs the concert in the movie, sings this ditty twice.

The second time, the third line is changed: "It's better to burn out 'cause rust never sleeps." That sentiment, combined with the anguished expression on Young's close-up face, provides the picture with its title and with whatever meaning it may have. The theme of rust -- the constant, slow, subtle gnawing of mortality -- pops up again and again in this film released on the 10th anniversary of Woodstock.

The primary touchstone is the conscious memory of the festival. The opening scene of this fantasy recalls one of Woodstock's great moments, with a guitar playing "The Star-Spangled Banner" a la Jimi Hendrix, while the "roadies" who handle equipment march onstage and strike momentarily the Iwo Jima pose as they erect a giant and very phallic microphone, The roadies are clad in rust-colored, hooded robes, their faces unseen and their eyes glowing like the little desert creatures in "Star Wars."

After the Beatles' music opens the first half of the concert, Neil Young is seen waking up on top of a giant loudspeaker decorated to look like a steamer trunk. He sings solo, goes back to "sleep" to start the intermission, and in the second half sings with Crazy Horse backing him up. A comparison of his solo and ensemble work tends to confirm the axiom that less is more.

The theme of gigantism builds as Young appears with an enormous harmonica around his neck, and on the stage there is a glass of water four feet tall.

All the while, the "roadies" flit about, backstage and onstage, mysterious and hooded, hustling equipment, mimicking the performers and sometimes dancing.

Their function as symbols is unclear right up to the end, when they are dismantling the equipment and the ambivalent life symbolism of the beginning has given way to ambivalent death symbolism. Things seem to become clearer when the show personnel come out to take a final bow and one notices among their number a white-jacketed doctor and a man in a wheelchair. The doctor's presence is underlined by the final words of Young (who is, of course, no longer young): "Thanks Doc -- thanks a lot."

What does it all mean? as an experience for Neil Young fans -- who are its primary but not quite exclusive audience -- "Rust Never Sleeps" means a movie midway between a live concert (usually the worst way to hear rock music as music) and a recording (the best way).

But ultimately it means that Neil Young can occasionally be a powerful though somewhat unfocused poet -- in his sometimes Dylanesque and often eloquent lyrics. Often he seems to be using variations on the same basic tune -- but it is a good tune.