Pop aficionados often feel the need to be apologetic. Few would would openly admit to preferring those early bouncy Beatles singles to the Fab Four's more musically adventurous output of later years, or to having danced around the living room to "La Vida Loca." Even the shiny surfaces of Cornelius are subject to rigorous deconstruction on the pages of music magazines. Something so perfect, so subtle -- they reason -- must somehow transcend the realm of mere pop.

To assuage the guilty pleasure that pop music holds for the true music connoisseur, the suffix of avant, or avant garde, is often appended to the pop label as if something that is quirky or weird could somehow warrant one's attention more than something that is only pop.

The trio Slapp Happy, as the fliers for their upcoming Japanese tour attest, have been saddled with the avant-garde label since their first recording back in 1972.

It is partially warranted. The group, an international collaboration of German vocalist Dagmar Krause, Englishman Anthony Moore (guitar/keyboards/vocals), and American Peter Blegvad (guitar/vocals), had strong connections with the protest/progressive rock scene first in Germany and then in the U.K. Their first two albums were recorded with Faust, the kings of avant-garde/German progressive rock, and the next two were released on "Tubular Bells"-era Virgin Records, home to much of the time's more challenging music.

But "Casablanca Moon" (also known as "Acnalbasac Noom"), the best-known of their two early releases, is pure pop in the best sense: hummable, subtly ironic and slightly silly. Krause described Slapp Happy in a recent interview from the group's base in the U.K.'s "surreal pop," but Blegvad's description of their music gets closest to the Slapp Happy ambience: "Our ambivalence toward pop music expresses itself in a sinister kind of whimsy."

The title cut of "Casablanca Moon" pokes fun at Graham Greene-style romance and international intrigue, set against a tango background. A pop tribute to Michelangelo couples lyrics that would be at home in a children's book ("Work and toil, well he ain't no dilettante, he conceives in oil and Vatican chianti" goes one of the more memorable lines) with wah-wah guitar breaks. Like that exuberant moment at a party between cold sobriety and total intoxication, when conversation seems effortless and everyone is engaging, Slapp Happy bubbles with an eccentric wit and charm.

Though the group garnered a cult following among fellow musicians and critics, eccentricity did not bring Slapp Happy a larger audience. After the group's demise, all three members fooled around at the fringes of both avant-music (most notably with Fred Frith in Henry Cow with which Slapp Happy merged briefly) and also pop. Moore went on to produce Paul Young's "No Parlez" album, while Krause has become a noted interpreter of Bertolt Brecht songs. Blegvad has continued to beguile listeners with albums of ebullient, childlike pop.

Considering the group's on-again, off-again status, their latest release, "Ca Va," segues easily from their older material.

"Surprisingly little has changed," says Krause. "We still have a good chemistry together and still laugh a lot when we're working. In fact, when we meet up, it's hard to imagine that we were ever apart for so many years."

The silliness is still there as in "The Unborn," a chronicle of Byron's life in the womb. But more obvious on this record is a naive romanticism, a tendency in their previous works taken to soaring heights on "Ca Va." Krause's voice has grown more mellifluous and authoritative over time, lending the songs a certain bittersweet pathos. The opening lines of "Scarred for Life" -- "Leave me something to remember you by, more than a lock of your hair, leave me scarred for life, show me you really care" -- must stand as one of the more passionate epitaphs of doomed love.

If Slapp Happy remains musically consistent, the trio's stance toward live performance has taken a radical turn. In keeping with their ambivalence toward pop music, Blegvad and Moore had rejected touring when the band was first active in the '70s. Thus Slapp Happy's one live show was a rather bizarre spectacle at London's Institute of Contemporary Art in 1981.

"We must have been drunk with the euphoria of the reunion," says Krause, "because somehow we agreed to perform wearing luminous fish masks!"

Though "Ca Va" was released in the U.K. last year, Slapp Happy's Japan tour will be the first time in 20 years that the group has performed together.

"We had endless ideas about performing," says Krause, "but these ideas became so grand they were impractical to realize. I had seen for myself that there was such an interest here [in Japan] in Slapp Happy and its individual members that I thought that it would be quite wonderful to do a series of concerts with Peter and Anthony as a follow-on from 'Ca Va.' "

Their attitudes toward performance isn't the only thing that has changed.

"Maybe we were never desperate to have a hit record," says Krause, describing the group's uneasy relationship to pop. "Slapp Happy always seemed to transcend fashion, which is probably why we are still making records and hope to continue to do so. The songs are there and we wouldn't mind having a hit record -- even now!"