TOMORROW NIGHT'S concert at Howard University's Cramton Auditorium is both a debut and a renewal. It will mark the unveiling of the Howard University Jazz Repertory Orchestra (under the direction of Arthur Dawkins) in an evening of music culled from the Billy Eckstine Big Band, a seminal unit from the mid-'40s that proved to be an incubator for the revolutionary jazz style known as bebop. Although the band lasted less than three years, its impact on musicians was enormous: Dizzy Gillespie was its musical director, Charlie Parker its principal soloist.

Among those who were in the band: Sonny Stitt, Dexter Gordon, Miles Davis, Gene Ammons, Fats Navarro, Art Blakey, Tadd Dameron, Sarah Vaughan and Lucky Thompson.

A link between then and now is Washington pianist John Malachi, one of several arranger/musicians for the Eckstine band in 1944 and 1945. On the music faculty at Howard since 1979, (he also plays five nights a week at the 219 Restaurant in Alexandria), Malachi recalls the heady days when the big band was making great music and getting little public acclaim, though he sensed something special. "The whole band did! As a matter of fact, the problem was nobody did but us, which is why the band didn't last. Oddly enough, and it sounds very stupid and silly to me now, we were considered some sort of avant-garde musicians.

"Of course, we didn't feel that way, but we were all young. The oldest was Eckstine, he was 29; Dizzy was 26, Charlie Parker was 22, Sarah Vaughan was 20, Gene Ammons was about 18. We were just a crazy bunch of young kids doing what we liked; we knew there wasn't a trumpet player alive that could play better than Dizzy. We were really obsessed with what we were doing, it was our sound, as far as we were concerned. But Dizzy was considered by critics and audiences some kind of weird crazy comic or something. People didn't even like Sarah, and they thought even less of Charlie Parker -- nobody was willing to bear with him."

The instrumental aspects of the Eckstine band were under-recorded, Malachi says, because "during that time, the record companies weren't very interested in that bebop-type music. They were more interested in the vocals, and at that time Billy Eckstine was the principal commercial part of the band." Mr. B, as Eckstine was known, was in fact one of the most popular recordings artists of his time, using his drawing power to support the big band. The main attraction in the fabled Earl Hines band, Eckstine had a working knowledge of trumpet and trombone, but a strong intuition for fresh, significant sounds; he used his popularity to create a larger audience for jazz.

For the Howard concert (which is free), Malachi and another Howard faculty member, Reppard Stone, had to reconstruct charts through transcriptions. "It seems as if all the charts had been destroyed or lost," Malachi says. He reworked his own "Opus X," one of the band's first distinctive tunes, by listening to the recording of an old radio broadcast. "It's like looking at a photograph of yourself when you were 21," he muses.

Tomorrow, Malachi will be joined by one other Eckstine veteran, tenor saxophonist Charlie Rouse, who went on to become Thelonious Monk's favorite sideman. Other musicians include saxophonists Buck Hill, George Woods (the only undergraduate) and Charlie Young (of the Navy Band's Commodores); trombonists Curtis Fuller and Calvin Jones, trumpeter Tom Williams; drummer Grady Tate and world-renowned bassist Ron Carter. According to Dawkins, "we chose people whom we thought were most indicative of the bebop style . . . and they were predominantly professionals because of limited rehearsal time."

The Eckstine tribute is the first of its kind, while the orchestra, despite the floating status of some of its members, is the first major black repertory company in this country. In the past 10 years, from the time Donald Byrd joined the music faculty, Howard has been developing a reputation to match the one its choral organizations have had for four decades: Last year members of the Howard Jazz Ensemble won four major Down Beat collegiate awards, including one for best overall soloist (Roger Woods).

The orchestra is jointly sponsored by the National Endowment for the Arts, the D.C. Commission on the Arts and Humanities and Howard University. For Dawkins, who succeeded Byrd in 1975, it represents a two-year dream inspired "specifically because John Malachi was on the faculty and because he was very knowledgeable about that period of music. Those early periods tend to be overlooked. We'll probably go as far back as Fletcher Henderson, and I think we're probably more concerned with the past than the newer things."