Acts such as R.E.M., the Swimming Pool Q's, the dBs, Let's Active, Don Dixon, Guadalcanal Diary, Fetchin' Bones and Pylon share more than just the geography of the Atlantic Coast Conference and a common pool of producers. They share a deep ambivalence about the changes that are sweeping across the New South.

These young new wavers have all escaped the stifling constraints of small town life in the South. But they realize they have lost an invaluable sense of rootedness in the process. Again and again in their songs, a feeling of liberation is haunted by a sense of loss.

The pastoral past of the South is represented in these songs by jangly folk-rock guitars and swelling harmonies borrowed from the Byrds. The urban future can be heard in jarring rhythms and deadpan vocals reminiscent of the Velvet Underground. The collision of these two styles -- and the social forces they represent -- gives southeastern rock its distinctive sound.

The most popular of these bands is R.E.M., thanks largely to the guitar ingenuity of Peter Buck. A sorcerer with guitar riffs, Buck conjures up dense, moody atmospheres that are driven home by a galloping rhythm section. Unfortunately, the foreground is taken up by Michael Stipe's mumbling vocals. For years, college radio listeners have assumed that Stipe's self-important murmurings contain profundities, but the suspicion grows that he mumbles because he has nothing to say.

Another Georgia band, Atlanta's Swimming Pool Q's, is far more satisfying. Lead guitarist Bob Elsey is as adept as Buck at inventing memorable guitar figures, and the rhythm section is every bit as muscular as R.E.M.'s. Instead of Stipe's garbled stream-of-consciousness, though, the SPQ's boast southeastern rock's best lyricist in the literate, insightful Jeff Calder and the genre's best lead singer in the stunning alto Anne Richmond Boston.

The Swimming Pool Q's, who appear at the 9:30 club tonight, have followed their brilliant self-titled 1984 album with the just-as-good "Blue Tomorrow" (A&M SP 5107). Though it was produced by Britain's new wave hot-shot Mike Howlett (A Flock of Seagulls, the Alarm), the album reflects the band's longtime live show, a heady mix of Captain Beefheart weirdness and Mamas and Papas harmonies.

Calder once studied writing with novelist Harry Crews, and he has a sharp eye for the changing face of the South. of the region; he lustily describes his girlfriend as "a big fat tractor, three wheels of steam and rust."

The contradictions between the past and future are brought to a head in several dreamlike songs. In "Wreck Around," the singer "drives through a group of new buildings on what used to be the edge of town." He watches these changes through the perspective of a five-and-ten window; suddenly the glass bends and the past comes crashing down "in a wreck around me."

On "A Dream in Gray" Calder describes his small-town roots: "I had to be from someplace . . . so I could have a place I could not go back to." On the title song, these vanishing roots are personified by an ex-girlfriend who pulls a ribbon from her hair "down in South Carolina in the shade of an old oak tree." On his best recorded vocal ever, Calder describes his restless wanderings in a doomed search to recover those roots. Elsey's lead guitar is so melodic and expressive that it's almost like a duet vocal.

North Carolina's Mitch Easter has produced some important southeastern rock records for R.E.M., the dBs and Pylon, but Easter himself seems to be turning into a southern version of Todd Rundgren: a brilliant engineer and imaginative musician who is content to turn out gemlike but pointless re-creations of '60s British rock styles.

Easter has recorded with a trio called Let's Active, but now he has dispensed with his rhythm section and has recorded Let's Active's third release, "Big Plans for Everybody" (I.R.S., 5703), as a solo album. Writing, singing and playing almost everything by himself, Easter does have a way with perky melodic hooks and Beatlesque transitions. Yet this record has the claustrophobic feel of too many one-man albums; it's as if Easter were only singing to himself.

A much fresher variation on the southeastern rock sound is supplied by North Carolina's Fetchin' Bones, who appear at the 9:30 club Saturday. This new quintet brings the convulsive aggression of hard core to bear on the neo-folk rock, as if X had tackled the R.E.M. songbook.

Don Dixon, who produced albums for R.E.M. and Guadalcanal Diary, handled the knobs for Fetchin' Bones' debut album, "Cabin Flounder" (DB 77). The group's distinctive personality is established by Hope Nicholls, whose lead vocals are so agitated they turn every moment into a crisis. The two guitarists, Gary White and Aaron Pitkin, often give the song a folksy, countryish flavor, which then gets caught up in Nicholls' impatient intensity. The rhythm section then begins to jerk this way and that under Nicholls' influence. It's as if the pastoral constancy of the South were suddenly attacked by the 20th century in each song.