THE SAN FRANCISCO Ballet is America's oldest ballet company, and certainly one of its most appealing. Maybe it's their proximity to sun and surf, but the San Franciscans have always had a buoyant, athletic air, and a gift for the dramatic.

Over its 54 years of existence, the troupe has had the good fortune to have been directed by a succession of forceful and distinctive personalities. Lew Christensen, one of this country's first and finest male ballet dancers and a strong choreographer, established a close and enduring link between the New York City Ballet (with which he had danced) and the San Francisco Ballet. Michael Smuin brought out the dramatic gifts of the dancers, creating flamboyant spectacles like "A Song for Dead Warriors" and "The Tempest."

Today the company is headed by former New York City Ballet principal Helgi Tomasson, a regal Finn who's been lauded for his neo-classical works, his technical acumen, and his commissioning of adventurous works by contemporary choreographers.

The San Franciscans' two programs at Wolf Trap this weekend are an alluring mix of new and familiar works. Friday's performance includes Tomasson's elegant "Menuetto," to music by Mozart; Christensen's "Divertissement d'Auber"; the "Rubies" section from George Balanchine's "Jewels," set to Stravinsky's pungent score; and "New Sleep," one of angry young man William Forsythe's disturbing and dreamlike dances, with an electronic score by Tom Willems. Saturday's bill blends the Christensen and Forsythe pieces with Tomasson's "Concerto in D: Poulenc" and Balanchine's well-known "Theme and Variations," set to Tchaikovsky's equally familiar score. SAN FRANCISCO BALLET --

Performing Friday and Saturday at Wolf Trap.