How many times have you sat stewing at a concert, holding in your comments and criticisms, feeling hampered by the formal atmosphere? The Dance Exchange's "Evening of Exchange" series unwraps the straitjacket. Informal in both format and performance style (minimal costumes, sets and lights), these Friday-night gatherings encourage audience response and explanations from the performers.

This Friday's event, "Paring Down and Pairing Up," focuses on solo and duet forms: Why does a performer choose to work alone? How are partnerships created and sustained?

Representing the soloist sensibility are choreographer/dancers Cathy Paine and Diane Floyd, and actress Isabel-Lee Malone. Paine will dance to a William Walton score; Floyd's work, along with Daithi Sproule's musical accompaniment, is based on images from Sylvia Plath's "The Bell Jar." Malone will perform "Lola's Piece," an autobiographical monologue about the shock and loss experienced after a close friend's death.

Three young and innovative duos -- Duets Etc. (Helen Rea and Don Zuckerman), Triple Time (Debra Kanter and Teddy Klaus) and New Moves (Tish Carter and Nancy Galeota) -- have worked out very different notions of partnership. Duets Etc. emphasizes silky, intimate dancing, and performs works by a wide range of top- notch choreographers. Triple Time, a husband/wife, composer/dancer team, exhibits a fine sense of humor, play and rhythm. New Moves opts for words, repetitive gestures and bizarre props -- in this case, all sorts of springs and Slinky toys. Be ready to look and listen hard, ask questions and sound off. PARING DOWN AND PAIRING UP -- This Friday at 8 at the Dance Exchange Studio, Lansburgh Building, Seventh and D streets NW. $5. Call 783-8900.