Generally, opening acts at rock concerts are cannon fodder. They take the stage while many ticket-holders are still stuck at the parking entrances or finding their seats after arriving fashionably late. Their job is to warm the crowd up for the main event and then get off. It's not easy, but the exposure is worth it and sometimes the audience is treated to a genuine talent.

Anyone going to tonight's Foreigner show at the Capital Center should make it a point to get there by 8 to catch The Cars.

The Cars are a Boston band with one foot in punk music and the other planted firmly in the roots of American rock 'n' roll. Don't let their David Bowie-like vocals fool you. The Cars are pure rockers.

Their name indicates their feel for pre-Beatle pop music themes and their self titled debut album split time between sexually expressive lyrics and attempts at more complicated concepts.

Yet The Cars are more important than most new bands reshaping old songs. The Cars are the first visible proof that "new wave" music is getting a second wind. They are not punk, but their style owes as much to the cacophony of the Sex Pistols as to the structured pounding of bands like Mitch Ryder and the Detroit Wheels and the early J. Geils Band.

It's not surprising that a bit of fellow Bostonian J. Geils shows up in their sound. Cars' guitarist Elliot Easton often uses the simple but effective stingers and lead riffs that bands like J. Geils and Aerosmith - another Boston breakout - rode to early successes.

The Cars' songs are more lyrically sophisticated than either Geils or Aerosmith, and it is that other dimension that makes the band so potentially powerful. Drummer David Robinson spent some time with Jonathan Richman and the Modern Lovers, and some of the Modern Lovers' quirky urbanity shows up in The Cars.

Musically, The Cars are far deeper than any of the punk acts. Besides Easton's prowess, Benjamin Orr (bass), Greg Hawkes (keyboard) and Robinson provide a full-bodied rhythm section while Ocasek offers the band's visual focus. All this makes for an interesting, if not yet fully realized, performance.

It should be pointed out that "The Cars" is not a great album. At its best ("Just What I Needed," "You're All I've Got Tonight"), the album is a driving mix of old and new. At its worst ("Don't Cha Stop"), the melodies are repetitive and dull. Still, the band is already getting good airplay and offers a fresh perspective on some time-worn ideas.

Another high tide in the "new wave" is Talking Heads' second release, "More Songs About Building and Food".

Their first album, "Talking Heads: '77," drew praise usually heard only at funerals and bar mitzvahs, but the band never caught on commercially. Unfortunately, this work is not likely to catch on either, but the group has developed and should be heard.

Unlike The Cars, who are basically step-children of the punk movement, Talking Heads have been around from the start. They've run the full gamut, from gigs at New York's CBGB's to denial that they were punk at all. The facts is that they weren't and aren't, and "More Songs About Buildings and Food" is proof that they are influenced much more by classic hits than new postures.

Producer and synthesizer whiz Brian Eno has greatly enhanced the quartet's sound and the band members have markedly improved their own playing. This record is stronger than "The Cars" but will probably miss the masses due to David Byrne's voice - which takes some getting used to - and an eccentric use of tempos that often fractures seemingly predictable runs into strange pieces. This music is not pre-fab, and Byrne's lyrics are usually even more demanding than the melodies.

Like The Cars' David Robinson, Talking Head keyboardist Jerry Harrison was a Modern Lover and Harrison't influence on his ensemble is more overt than Robinson's effect on his. Categorically, Talking Heads comes closer to "art rock" than most groups that ever used that term, and they have been pegged as a cult band because of it.

The Cars are more accessible than Talking Heads because The Cars'd feelings are up front and you can dance to their tunes when you don't want to think about them. Talking Heads come at you from the other end. Instead of "get up and boogie," their songs say "sit down and listen."

So, tonight, boogie to The Cars. Later, listen to Talking Heads. They're both saying some things you ought to know about.