Every time vibraphonist Milt Jackson has performed in Washington in the last year he's had to labor under the hadnicap of working with unfamiliar pickup groups.

It's different this week at Blues Alley, where he's appearing with pianist Cedar Walton, bassist Sam Jones and drummer Billy Higgins - musicians he's worked with frequently over the last decade.And the musical results are rewarding.

Their program on Monday's opening night included a variety of popular standards and jazz originals - "Misty" and "Speedball," "I Got it Bad" and "Blue Bossa." Jackson was up to his usual high lyricl standard. Walton's melodic lines were bright and sprightly. Jones provided a strong foundation and Higgins supplied crisp, infectious rhythms.

Jackson was vibraphonist for the now-defunct Modern Jazz Quartet, an ensemble that took chamber jazz to a level it hasn't experienced since. But Jackson was dissatisfied playing tightly arranged music. So the group broke up in 1974 after 22 years together.

"I had no fascination for Bach," said the vibraphonist in a reference to the group's frequent use of counterpoint and polyphony. "I have more peace of mind now than I've ever had. I play the music I want to hear."

Still, the MJQ reunited last fall for a brief tour of the South and Midwest. A tour of the West Coast is upcoming. And the group will perform at Carnegie Hall with the Kansas City Philharmonic on Jan. 25.

Jackson's appearance through Saturday marks the beginning of a new music policy at Blues Alley. Musicians will be booked to perform with their own groups. Previously, artists were accompanied by a house trio.

John Dimitriou, who managed the Show boat Lounge until November, ismanaging and booking performers for Blues Alley. He said the emphasis will be on modern jazz and he has already booked the Heath Brothers, Carmen McRae, Gerry Mulligan, Nat Adderley, Betty Carter, Hank Crawford and Dizzy Gillespie.

The room has also been remodeled to increase the seating capacity from 160 to 190.