CGI 'Chipmunks' run out of gas pretty fast

At an Alvin and the Chipmunks concert, every seat is a bad seat.

"Alvin and the Chipmunks" turns its titular rodents into the hottest helium-voice boy band since 'N Sync. But the comparative enormousness of their human backup dancers makes their talents seem especially tiny.

The film engages for about 30 minutes, or about 10 minutes longer than you might expect. This picture, after all, has only one idea: chipmunks that talk and sing. It's the same idea that fueled novelty recordings and a 1980s cartoon series.

In the movie version, computer-generated critters Alvin, Simon and Theodore (voiced, in fast-forward, by Justin Long, Matthew Gray Gubler and Jesse McCartney) interact with humans in a live-action world. The chipmunks are quite cute, especially young, wide-eyed Theodore. The humans ... well, they appear to be looking in the general direction of the CGI animals, and that always helps.

The brothers chipmunk are happily singing and storing nuts when their tree gets chopped down by a Christmas-tree company.

Their odyssey leads to Los Angeles, and as crazy chipmunk luck would have it, to the home of a fledgling songwriter named Dave (Jason Lee).

As Dave's visitors try to keep their presence hidden from him, "Alvin and the Chipmunks" offers physical gags young kids will enjoy. But the film soon reveals the limits of its live-action format (and perhaps its budget).

Youngsters accustomed to elaborate chase scenes in animated films aren't likely to be thrilled for long by the chipmunks' more modest exploits. And flatulence humor, though always appreciated by the 4-year-old set, only goes so far.

There's also too much emphasis on the record industry and the chipmunks' careers. Dave worries that a smarmy record executive (David Cross) is exploiting the chipmunks by commercializing their image.

That's pretty rich coming from a movie based on a fake-chipmunk novelty act. Suddenly, the Alvin and the Chipmunks brand is all about the art.

Cross makes a decent foil for nice-guy Dave, and Lee effectively taps his likable-doofus qualities from his hit TV series "My Name Is Earl" in a few scenes.

But on the whole, "Alvin and the Chipmunks" isn't a resume builder for anyone involved.