If fanatical KISS devotees want to see big-screen footage of one of the band's legendary 1970s concerts, they may be disappointed to discover that that's not what "Detroit Rock City" is all about.

In fact, the group doesn't even put in an appearance in the film until the very end, except for the presence of several of their songs on the musical score.

To tell the truth, this period comedy is more like a '70s-era "I Wanna Hold Your Hand" (a light 1978 comedy with a similar premise about the Beatles in the mid-'60s) but with much more raunchiness and profane language.

Also, you can't help feeling that in their zeal to get the flavor of the time and place, the filmmakers have neglected other, equally important elements — such as a cohesive story line and a consistent tone.

Still, it really isn't that bad a film. Its heart is definitely in the right place and there's a handful of very funny sequences, as well as a series of appealing performances from members of the talented young cast, all of whom seem to be having a good time.

Leading the way are Edward Furlong, Sam Huntington, Giuseppe Andrews and James DeBello, who play, respectively, Hawk, Jam, Lex and Trip, four Ohio teens who sleep, eat and breathe KISS. The buddies are eagerly counting down the hours before they get to see the band play at a sold-out show in Detroit.

Unfortunately, fate seems to be conspiring against them, largely in the person of Jam's mother (Lin Shaye), who believes her son's heroes play "the devil's music." First, she destroys the prized concert tickets, then she grounds her hapless teen and sends him to a boarding school in an attempt to reform him.

But that's not enough to stop these diehard fans, who (evidently) win a radio-sponsored ticket contest and abduct Jam for an impromptu road trip. Needless to say, their troubles aren't over and each teen has to undergo a rite of passage to reach the desired destination.

Director Adam Rifkin ("The Chase") and first-time screenwriter Carl Dupre spend considerable time setting up these rites of passage. But in between the movie's opening and ending, many scenes seem poorly thought-out, and too often the humor aims low, stooping to cheap gags.

Fortunately, the performances are lively — both Furlong and Huntington are particularly good — and use of vintage period music (by KISS and many other acts of the time) helps, as does some inventive camera work.

"Detroit Rock City" is rated R for considerable profanity, violence (including fist fights and a beating), simulated drug use (marijuana and other hallucinogens), female nudity and male partial nudity, vulgar flatulence humor and use of crude slang terms, brief gore (from some of Gene Simmons' on-stage antics) and use of some ethnic slurs.