"Great Jazz Pianos" at Wolf Trap Saturday night was an interesting idea: to gather some big hitters in the big-league world of Jazz piano -- Eubie Blake, Marian McPartland, Teddy Wilson and George Shearing -- each of whom represents a different era in jazz, from rag to swing to modern. The diversity to styles aside, there was no thread of consistent quality. But the evening, telecast live on public television, was not without its rewards.

Show-opener Eubie Blake, the 96-year-old ragtimer, deserved his standing ovations -- deserved, that is, for his past efforts in the art of advancing jazz music. If Blake's rag piano was slightly tired, especially in the arpeggios on "Memories From You," his vehicle now is not his jazz but this charming stage manner and the novelty of his age.

But when Marian McPartland opened with her standard, "Sweet 'n' Lovely," you soon saw the exciting possibilities of the tradition Blake established. What great jazz! Her attack was modern and daring, each chord romantic in contrast to the next, trading phrases with her fine sidemen, drummer Rusty Jones and bassist Steve La Spica. But unlike so many modern jazzmen, McPartland never forgot her main task: to make you swing.

Unlike McPartland's explosive geometric style, Teddy Wilson's is linear, made exciting by his impeccable timing and light and graceful touch, embellished by intricate Art Tatum runs. The luminary of the Benny Goodman and Billie Holiday bands of the '30s Wilson gave on Saturday night lovely renditions of traditional standards -- "I Can't Get Started," "Stompin' at the Savoy", and "One O'Clock jump." A gem-like outing.

George Shearing's performance was uneven. He and his superb bassist, Brian Porff, wove a sophisticated dynamic pattern on "Lamp Is Low" and "Soon It's Gonna Rain" but when he strayed from his speciality, modern jazz, as in singing "Send in the Clowns," he stumbled. Despite the inconsistency, Shearing had his high points -- just like the evening itself