While the heavyweights of British New Wave (the Clash, Buzzcocks) are still stumbling in the gutter, the lightweights are performing with pomp and circumstance in the grandiose manner of arena rock. Although their music originally may have been motivated by a punky desire to fist-fight in dives, two of these English lightweights, the Police and Joe Jackson, share more than a common record label.

Both these rock acts have infiltrated America's AM mainstream, and each released two albums in 1979. The explanation for their success is a simple one: Unlike the breakneck kamikazes of English punk, their music was neither hyperactive nor overly kinetic. In fact, the debut albums by the Police and Joe Jackson are sparse and rather vacant affairs.

Earlier this year, the Police hit with "Roxanne," which at its best contained an emotional tug at the heart. Infatuated with Roxanne, a prostitute, the singer begs his beloved to put away her make-up ("you don't have to sell your body to the night"). Hardly a silly exercise like the Police's "Sally" (a song about a rubber love-doll), "Roxanne" is a moving expression of a heartbroken lover.

What made "Roxanne" especially significant, though, was its semi-reggae beat, which gave the Police a chunkier, thicker edge over the newer pop bands like the Cars and Cheap Tricks. On the Police's latest album, "Reggatta De Blanc" (A&M SP-4792), "Roxanne" can be heard in every groove -- but only its sound, not its substance.

"Message in a Bottle," the current hit, seems more influenced by calypso rhythms than reggae. It's like a soft Jamaican breeze whispering an instant metaphor ("sending out an SOS") for quick-and-easy identification by teenagers. Furthermore, the album's title cut sounds like Belafonte at a pep rally singing "The Banana Boat Song."

Yet the Police's stye isn't really a usurption of reggae as much as it is an attempt to establish a sense of authenticity about their sound, as if it had actually sprouted from the soil of a tribal community.

As with most bands experiencing growing pains, the Police's second effort is not quite as raw as their first -- a Top-40 hit practically forces a rock group to reach for the platinum trophy with some spit and polish. There are certainly several future hit singles on "Reggatta" -- "The Bed's Too Big Without You" (if only because it's the next logical step after "Roxanne"), "Does Everyone Stare" (mock-operatic mush a la Queen), and "No Time This Time" (the "Batman" theme song with gargling noises). Unfortunately, there's nothing on it as crazed as "Masoko Tanga," an experimental showcase for the Police's form of pop reggae that concluded their debut, "Outlandos D'Amour" (A&M SP4753).

Similarly, Joe Jackson's first release, "Look Sharp!" (A&M SP4743), is where one should properly be introduced to Jackson's plain-ol'-Joe prose. It's a perfect rock album for bureaucrats -- tidy, without any sloppy edges, non-threatening, and as contented as Morris the Cat.

Although he uniquely resembles one of the bug-eyed dwarfs in AIP's "The Invasion of the Saucer Men," Jackson has frequently been accused of being nothing more than a combined clone of spastic Elvis Costello and ex-pub rocker Graham Parker.

Even more cruelly, one critic dubbed Jackson modern rock's answer to Freddie Garrity, vocalist for Freddie and the Dreamers of the British Beat Era.

To be fair, though, Costello-Parker Jackson, et al were begat by Van Morrison, the master of the gruff exterior concealing a lonely figure sobbing in his ale at some dank pub. At times, Jackson's vigorous use of harmonica even recalls the style of Van Morrison's angry young Them, blowing their brains out on "Mystic Eyes."

But here, the comparison between '60s and modern British beat must end.

On "I'm the Man" (A&M SP4794), Jackson's aspiration is that of a songwriter, not that of an English lad desperately trying to cover American R&B material. As a singer, Jackson vocalizes with enough hoarseness to convey the tough image, but as a songwriter, he lacks the bite.

"On Your Radio" is Jackson's response to the AM success of his "Is She Really Going Out With Him?" but it slinks away from the attack in the opposite direction of Elvis Costello's "Radio Radio." On "Geraldine and John," Jackson aims for the same middle-class targets as Ray Davies, but by avoiding any direct pokes at the ribs, he comes off sounding extremely snide. "It's Different for Girls," a dainty ditty that seems to spiral indefinitely, finally comes to a halt only as a cute curtsy.

In contrast, the title cut jerks with such an angry grip that the entire album almost falls into place. With the line "'cause I got the trash and you got the cash," Jackson practically sets himself up for a critical wisecrack.

But the urgency behind the message (a protest against scams such as the hula-hoop and safety-pin rock) pushes the song into a well-balanced blend of humor and hysteria, easily Jackson's best song to date. One can only chortle when Jackson pants, "I had a giant rubber shark and it really made a mark/Didja looka looka lookit alla blood!"

Joe Jackson's sharp-and-snazzy image, however, can become quite irritating.

On the lyric sheet for "I'm the Man," the words "a pop song" are printed in parentheses next to a couple of song titles. What does that make the other songs on the album . . . jazz?