Jazz pianist, composer, educator and arts lobbyist Billy Taylor hasn't lived in Washington for many years, but he's spent so much time here -- as a council member with the National Endowment for the Arts and as a performer in local clubs -- that it's only fitting he finally receive the key to the city he grew up in. Today he will be honored by Mayor Marion Barry, who has declared this "Billy Taylor Day." The day will end with a special concert at the University of the District of Columbia featuring local jazz stars performing Taylor compositions and Taylor with his own trio.

Rather than a key to the city, Taylor could use a couple of extra hours in the day; 24 just don't seem to be enough for someone who is constantly juggling the art and the politics of jazz. For instance, Taylor recently won a prestigious Peabody Award for his work as host and producer of National Public Radio's immensely successful "Jazz Alive" series; he's signed on for a number of arts segments on "Sunday Morning With Charles Kuralt"; and he's finishing up a book that will be published to coincide with an early 1982 NPR series, "The History of Jazz Piano."

The book is a rewrite of the pianist's doctoral thesis, "taking out some of the stuff you have to put in to get it past your doctoral committee," Taylor says good-naturedly. "It's a tracing of the history and development of jazz piano from its African roots to the present, with me as an eyewitness to much of what I'm talking about." A double take brings the assurance that Taylor, now 60 but looking 20 years younger, really has been around . . . and in the right place, much of the time.

That includes Washington in the '30s when the Dunbar high school student drifted away from the ball fields to make "a serious commitment to playing piano. It was a fabulous place to grow up. I had access to many of the greats that came through; people don't have that anymore. I had personal contact with Jelly Roll Morton, Count Basie, Duke Ellington, people I otherwise would have known only through recordings or on the radio."

Taylor came from a family of pianists; his grandfather was a founder of the Florida Avenue Baptist Church, where his father was the choir conductor. Two uncles were pianists and "there was a lot of music at my house." After Dunbar, Taylor graduated from Virginia State with a degree in music, but his postgraduate training came in the '50s on New York's Street of Jazz, 52nd Street; for several years he was house pianist at the legendary Birdland. To a jazz musician that was like gigging in heaven ("to say the least!"). Taylor played behind every notable jazz star of the day, and his pickup bands weren't lacking in talent, either. "The all-star groups were made up of whoever happened to be off that week -- Gerry Mulligan, Oscar Pettiford, Lee Konitz, J.J. Johnson, players like that," Taylor remembers with a smile.

Over the years, Taylor has served as musical director for the "David Frost Show," written a "Suite for Jazz Piano and Orchestra" commissioned by the Utah Symphony, and last Sunday was the world premiere of his "Make a Joyful Noise," a work in the Ellington Sacred Concert Tradition performed with the Indiana Symphony. There have been dozens of records and a full performance schedule. "I don't like to travel that much," Taylor admits, "but I do like to play that much."

Ironically, it's as an educator, organizer, fund-raiser and lobbyist that Taylor has become best known. One of his finest achievements is the 17-year-old Jazzmobile program in New York in which musicians perform on mobile units and then give workshops for the neighborhood youth. Like the award-winning NPR series, Jazzmobile is likely to suffer from extensive Reagan budget cuts in the arts programs. "Jazz will survive; it never had a lot of money to begin with," Taylor says sadly. "It means we have to do a lot less and serve a lot less people. It's frustrating, given the ground we have gained over the last few years. The thing that offends me is people looking at this as a handout. I don't think in government funding you can find anything that compares in terms of what you get for your buck." Taylor pauses for a moment. "You certainly don't get that in the military. We don't have cost overruns."

At 1 p.m. today, there will be a free concert and testimonial at Roosevelt High School featuring the UDC Jazz Band, the Howard University Jazz Band and the Jazz Band of the Duke Ellington School for the Performing Arts