A RECENT AD in Rolling Stone touted a new band from Ireland as "Standing between you and assembly line rock." Apparently wishing to dissociate itself from the squadrons of European bands flying in with the new "dance" sound, U2 could succeed even without Irish passports. The group has the superbly danceable beat of Ul-travox, replacing only the flashy electronics and crisp engineering of the high-tech groups, with the simple melodic energy of the best sort of folk music.

The synthesizer beginning "Tomorrow" off the new album whines with the timbre of an hautboy or other traditional reed instrument. With melodies evoking the charm of an unassuming folk tune, most of the album's songs center around a long gliding refrain of three or four notes, which lead singer Bono produces with an almost yodeling quality to his voice. In "Is that all?" Bono seems to be rejecting pat classification. "You think this song makes me angry...Is that all?" But the guitar played by the Edge sounds distinctly like the Clash riff from "Running," and the guitarist's name follows the tradition of the Police's Sting. Their respective riffs and even bass line give away U2's origins, nowhere else but New Wave. Yet, the drums Larry beats so maniacally in "I threw a brick" echo, and Adam Clayton's piano filters through indistinctly in the "October" intro. These effects make the music fuller and subtler than the whinings of New Wave groups, striving for a minimal instrumental texture.

And America has responded well to the U2 formula. The group's first album, Boy, received much airplay, especially around Boston. Songs like "I will follow" become hits and "Gloria" off the new album is already turning up on the dial. The songs provide a welcome variety among the hits on BCN, but their weaknesses becomes apparent easily. The "formula" threatens to imprison U2 in a musical cul-de-sac. Though the melodies and intros alternate between tracks, the style remains immutable. After a while The Edge seems to repeat the same riffs, and Bono seems to sing nothing but "faaaalling" and "reeejoice."

The repetitious sections could find excuse with some sort of leitmotif, but October lacks a discernable theme. It appears rather that the group can only deal with permutations of a certain group of notes, and they choose their refrain words only to have vowels long enough to stretch over the melodies.

THE ENTIRE ALBUM suffers from any comparison to the first album Boy and it deals with a wider variety of rhythms and melodies in songs like "Ocean" and "Electric Co." October has some additional instrumentation, but sticks more to the now-established formula. People forgive a lack of innovation in traditional folk music, but the rock world is faster paced, and failure to generate new ideas could spell out a group's doom, a problem in particular for New Wave groups who deal with a more limited range of permissible rhythms.

"Gloria" has interweaving melody lines in the vein of a Gregorian chant, and "Scarlet" has an appealing marching rhythm. But U2 simply superimposes these effects on the music when they should give the changes precedence. The Dublin sound was fresh and new but rapidly stagnating. Though U2 gained a foothold in the American market by accenting their insular origin, they must develop something beyond their formula to hold onto their popularity. Otherwise they will suffer the fate of ephemeral bands like the Knack and glide right back into obscurity.