"Basie was cool and laid back," says Thad Jones, who spent almost a decade with the late pianist's band, "but he was aware of everything that was going on all the time. Not only aware, but concerned. We thought of it as our band, that's the kind of feeling that he generated in everybody . . . That's true genius."

Jones, who was in the band's trumpet section from 1954 until 1963, recently returned from seven years in Denmark, where he was leader of the Danish Radio Orchestra. He is once again with the Count Basie Orchestra, this time as its newly appointed leader. The Washington area will be treated to two nights of the 16-piece group when it performs tomorrow and Sunday at 8 at The Barns at Wolf Trap.

"My whole childhood was spent right there in Pontiac [Mich.]," says Jones, whose two brothers, drummer Elvin and pianist Hank, are also prominent members of the international jazz community, "and my parents died right there." There were three sisters as well, "all musically inclined," and "there was always the sound of the piano and the radio, which was our main source of entertainment."

Acquiring his first horn, a gift from a trumpet-playing uncle, at age 13, Jones was already listening closely to Louis Armstrong, whom he considers his major inspiration. "I thought there was nothing more exciting than the sound of him playing the trumpet," he says. "Naturally I wasn't too aware of the kind of technical facility that enabled him to do all those things he could do, but later on it began to sink in after I began to try to learn the trumpet myself." That first horn, Jones says, did not come with a case, so he carried it in a paper sack. Michigan winters presented problems. "There were several rather embarrassing moments when I had to sit there and wait until my valves thawed out before I could get up on the bandstand with the rest of the guys."

The Detroit jazz scene, only 24 miles down the road, was already flourishing in the 1940s, and Jones and his brothers were drawn into its orbit. Saxophonists Yusef Lateef and Billy Mitchell and pianists Tommy Flanagan and Barry Harris were several of the many musicians Jones worked with. His first big-band experience came in army bands, one of which was led by Jack Teagarden Jr., son of the great trombonist. A highly regarded arranger and composer, Jones has written for the orchestras of Harry James and George Russell, the Charles Mingus Jazz Workshop, the Basie band and the Thad Jones-Mel Lewis Orchestra.

He contributed many solos during his nine years with the Basie band, but one cut stands out, the title tune of the 1955 LP "April in Paris," which immediately became a hit 45 and earlier this year was elected to the Grammy Hall of Fame. "Each time we did a take," Jones says of the session that produced the number, "I would come up with a different solo that Norman Granz, our producer, didn't seem to care for. By the time we got to, say, take 22, I was a little tired, and I said to trumpeter Snookie Young, 'This time I'm just going to play the first thing that pops into my mind.' So when my solo came around I just started playing this 'Pop Goes the Weasel' bit, and when we finished, Norman said, 'That's fantastic! That's the take, we'll keep it!' "