DOCTOR NIGHTLIFE has noticed an appropriate new-rock heartbeat in O-Positive's music: It's clever, just adrenaline-threatening enough without being too suave. Perfect summer night top-down music for now doctors (Thursday at the 9:30 club; $8, 393-0930). Elsewhere: FRIDAY


Koko Taylor has more hip credentials than most blues women can shake their sticks at -- the original "Wang Dang Doodle," a spot on David Letterman, and now a cameo (and two songs) in David Lynch's champeen Cannes'-tender, "Wild at Heart." And she's recorded a cover of a 15-year-old Ted Nugent semi-hit called "Hey Baby." That's great coffee! Taylor appears through Sunday at Blues Alley ($15; 337-4141).


It's the first-ever surf spectacular at d.c. space, and only the truly Venture-ous need snorkle over. First up, Untamed Youth (from that high mecca of high curls, Missouri), an all-instrumental surf-cover band from the A-Bones' Norton Records; then Washington's Godzilla grunge-rockers Monsters from the Surf. We recommend you wear flip-flops so you can get that authentic seaweed-between-the-toes sensation ($5; 347-1445).


To keep from getting too user-friendly, Hanson huggy Brother Mike Cotter and R&B/jazz bassist Chuck Underwood, coming off the road after a year and a half in relief of Patti LaBelle, have formed a new quartet specializing in slightly off-rock: John Hiatt, Warren Zevon, NRBQ, Randy Newman, Graham Parker, etc. And to back 'em up, they're Playing Favorites with the rhythm section of Mike Aubin and John Dawson (at Durty Nelly's; 652-1444).


The Montana Logging and Ballet Company (they're really from Montana but no, they don't perform "Swan Lake" as a log roll) appears in a satirical performance to benefit Grandma's House for children with AIDS. The show starts at 8 at the Metropolitan Memorial Methodist Church, 3401 Nebraska Ave. NW ($10; 363-4900).


Lorrie Morgan doesn't mind being in the hot spot: She followed her father George into the Grand Ole Opry company, she followed country queen Tammy Wynette into George Jones's duets . . . and she plays third base on her touring band's softball team. Loretta Lynn Morgan -- pure coincidence, but she did make her debut at 13 -- and new-country crooner Clint Black are part of the Alabama bandwagon coming through Patriot Center ($20; 432-0200). SATURDAY


Since his appearance at the benefit held in his honor here last August, rockabilly pioneer Charlie Feathers has been unable to perform at all because of debilitating diabetic neuropathy. This year the benefit that raises money for Feathers's soaring expenses is headlined by rocky-tonk pianist Becky Hobbs, a sort of great belle o' fire nicknamed "the Beckaroo." Other stars of the rockabilly fest are Washington's own Bobby Smith and Tex Rubinowitz, Vernon Taylor, Austin's High Noon, Todd Monroe and LesLee "Bird" Anderson (who had the great sense to get Danny Gatton to play guitar on her album). Also appearing are two of the area's new-generation country bands, Virginia & the Blue Dots and Go Cat Go. The show is 8 to 1 at the Severna Park Elks Lodge on Truck House Road; tickets ($20) at Joe's Record Paradise or Ferndale Oldies (for information call 301/544-5824).


Those gentle men of blues, "Bowling Green" John Cephas and "Harmonica Phil" Wiggins, perform an evening of Piedmont blues from their recent "Guitar Man" album at McLean's Alden Theatre ($12.50; 432-0200 or 790-9223). Cephas is a Washington native who fled the city for his family's old home territory near Fredericksburg; Wiggins has managed to stick it out here, thanks to the non-urban influences of Cephas and longtime partner Flora Molton. But then, he's young yet. SUNDAY


Wolf Trap's two-round Louisiana Swamp Romp includes a taste of all that good musical cookin' -- rocking Cajun zydeco, deep-bottom delta blues and fine, sensual Creole romance. The afternoon session ($12 general admission) stars fiddle-footed Michael Doucet and Beausoleil, squeezebox's First Son C. J. Chenier, and a special Black Top Records all-star ensemble called Ronnie Earl's Blues Party -- Earl and his Broadcasters plus Little Richard sideman Grady Gaines, James "Thunderbird" Davis and the legendary Earl King, author of the Mardi Gras anthem "Big Chief." Then at 8 it's Buckwheat Zydeco, Wayne Toups and the amazing, the mystical, the almost mythical Allan Toussaint, who almost singlehandedly created the spicy mix of Professor Longhair, carnival and R&B that is New Orleans music. Small wonder: He's a Neville connection, brother to the Mrs. (Naomi) Neville Linda Ronstadt made famous. Reserve seats $16, lawn $13 (for both shows call 432-0200 or 255-1860).


It's the first beer-and-burn all-day summerfest of the '90s at Wilmer's Park in Brandywine, featuring Solar Circus, the Jello Boys, the Zippers, Awakening, Transgressor and Love on Stage. Doors open at 11:30, music 1 to 10, no bottles or coolers allowed. Wilmer's Park is on Route 381 east of Route 301 (301/888-1600).