Baltimore is better known for its Inner Harbor than as a harbor for avant-garde performance groups. But a lively, if small, enclave of dancers, actors and performance artists has, during the past few years, sprung up in that city of row houses and Orioles. This weekend and all of next week, Washington audiences can experience their work.

The Washington Project for the Arts is presenting a Baltimore Series of Performance Art, beginning with Impossible Theater, Friday through Sunday, and continuing with The Tinklers and David Nez/Daniel Conrad, Wednesday through next Saturday. And over at the downtown YWCA this weekend, choreographer Diane Ramo and company will present a program of modern and jazz dances by Ramo and other Baltimore artists.

Impossible Theater, a collective of nine performers, employs a mix of images, media and influences to stretch traditional notions of performance. "City of Strangers," their latest work, incorporates sound, movement and visual and narrative material to create an alternately bleak and humorous vision of industrial and post-industrial urban life. Watching this piece, you'll see at one time or another (and sometimes simultaneously): panels flipping back and forth; huge projected slides of labor strikes, factory workers, Parisian cafe society and city nocturnes; bizarre drawings and diagrams; live figures dressed in white unitards and face- concealing hoods; and a multitude of other props.

You'll hear a multi-layered mix of words and music. Composer Bob Boilen has written a vivid, often jarring score, using both synthesized and primitive sound, overlaid with a narrative, some of it original, some of it taken from philosophical and literary sources.

Diane Ramo, once a D.C. resident active in the Dance Exchange's works, offers a more traditional form of performance -- pure, musically aligned dancing -- featuring three of her own works: "Jazz Suite," a trio of contrasting jazz dances set to music by Chick Corea, John Ramo and Elvis Costello; "Bravado Vivace," a more classical piece inspired by a Vivaldi concerto for mandolin; and "Event," a series of structured improvisations based on chance operations.

The company will also present two other works by Baltimore choreographers. The first, Diane DeFries' "Inertia," features a score by contemporary composer Lubomyr Melnyk. "Not Now," Bonnie Goldberg's study of time constraints and overwhelming pressure, unfolds to an unlikely mixture of music by Baltimore composer John Thompson, Frank Sinatra and The Flirts. IMPOSSIBLE THEATER -- Washington Project for the Arts, Seventh and D streets NW. This Friday and Saturday at 8 and 10. Sunday at 8. Admisssion $5, $4 students, over-65s and artists. Call 347-8304. DIANE RAMO AND COMPANY -- YWCA Penney Auditorium, 624 Ninth Street NW. This Friday and Saturday at 8. Sunday at 4. $6. Call 638-2100.