Of the dozen or so most important innovators in the history of jazz, perhaps a third to a half were like Charlie Parker, Bix Beiderbecke, and John Coltrane — roman candles who exploded on the scene, flared brilliantly with radical ideas, and burned themse lves out just as quickly.

Yet the music also has been dominated by worker drones like Duke Ellington, Benny Goodman, and Count Basie — guys who arrived at the office early, took care of business, and stayed late. They were all ceaselessly productive through good times and bad, and kept creating great music well into their 70s.

Trumpeter and bandleader John Birks Gillespie (1917–93) most assuredly belongs in the latter category. Although he earned the “Dizzy” nickname because of his tendency to clown around on the bandstand — to the consternation of his early employers but eventually to the delight of his audiences — Gillespie knew exactly what he was doing at every step of his development, both musically and professionally.

Now a new seven-CD boxed set from Mosaic Records, “The Verve/Philips Dizzy Gillespie Small Group Sessions” (www.mosaicrecords.com) presents Gillespie in a potentially difficult period of his life. In his late 30s and early 40s, he was no longer a young firebrand — the bop revolution he had helped bring about a few years earlier was here to stay — but he was still a long way from becoming, as he later proclaimed himse lf, “the elder statesman of bebop.”

More than half the material here emerges from Gillespie’s relationship with the producer and impresario Norman Granz. Donald Maggin, who wrote the most recent biography of the trumpeter (the fine “Dizzy: The Life and Times of John Birks Gillespie”), wrote that Gillespie’s artistry suffered in the early 1950s because he felt obligated to offer a more “commercial” kind of music, with emphasis on comedy and vocals. In fact, when Gillespie tried running his own record label in these years, the music it produced had more in common with R &B stars like Louis Jordan than it did with “serious” boppers like Parker.

When Gillespie began working with Granz in 1953, it turned out to be an ideal relationship: The producer featured the trumpeter in his famous jam sessions (both the recorded and the live variety), recorded him in special settings like orchestras and Afro-Cuban bands, and generally let him do whatever he wanted.

Granz helped Gillespie attain a new level of respect by letting him record without regard for the marketplace or the bottom line; yet like his hero and fellow visionary Louis Armst rong, Gillespie was a populist at heart — make that a “bopulist.” Virtually every session here contains an example of Dizzy’s crowdpleasing skills, his novelty songs (“Oo-Shoo-Be-Do-Be”), his entertaining vocals (“Oh, Lady Be Good”), and his knack for taking a hoary old chestnut and turning it on its ear for the amusement of an audience (never more so than on “Umbrella Man,” a loopy waltz from 1939 that Gillespie transformed into one of his most irresistible fun fests).

Gillespie also recorded frequently with his working bands of the period. Ironically, as the reissue producer Michael Cuscuna points out, most of Gillespie’s special projects have been reissued — such as his teaming with fellow stars Roy Eldridge and Stan Getz — but much of his equally excellent, bread-and-butter material with his regular “road” band is yet unheard in the CD era.

Cut over a 10-year period (for the last three, after Granz sold his label, Gillespie recorded for Philips), the box includes most or all of 13 LPs. The selections all feature Gillespie’s regular bands (in several cases in a live setting), with occasional guests like Duke Ellington’s star saxist, Johnny Hodges, on his own “Squatty Roo” and the vocal group the Double Six of Paris.

The set is remarkable in that it shows how consistently exciting and surprising Gillespie’s music was on a day-by-day, session-by-session basis, year in and year out. His intention and ability to constantly find worthwhile new sidemen to challenge him and keep him on his toes made sure of this.

Gillespie favored the trumpet-sax front line, but this set includes a marvelous series of sessions from 1959 in which he is the only horn, backed with a four-piece rhythm section featuring the guitarist (and occasional flutist) Les Spann, playing mostly original interpretations of pop standards.

Yet perhaps the most important collaborators are the composers. Gillespie was at least as gifted a writer as he was an instrumentalist, and many of his most durable works are included here, from the simple, effective “I Got Rhythm” variation “Salt Peanuts” to more complex works like “Night in Tunisia” and its pan-African follow-up, 1960’s evocative “Kush” (heard in several arrangements).

Like Woody Herman, whom Gillespie saluted in his early “Woody ‘n’ You,” Gillespie encouraged his sidemen to write and he played their works; pieces both famous and sadly neglected are here from such budding authors as Gigi Gryce (“Smoke Signals”), Benny Golson (“Out of the Past”), Tom McIntosh (“The Cup Bearers”), and Mr. Schifrin, whose pentatonic-sounding “Mount Olive” conjures a South American composer writing about Israel for an Afro-American jazz icon.

It may be Gillespie’s most durable accomplishment that, like his approximate contemporary Frank Sinatra, he made music that was at once great art and great showbiz. The Philips albums of 1962–64 — one of the more neglected bodies of work in Gillespie’s immense catalog — are a dynamic illustration of this.Two of these have him revisiting his past triumphs in very different formats: On the album “Something Old, Something New”he replays classic works of the early bop era, like “Dizzy Atmosphere” and “Good Bait,” while the album featuring the Double Six vocal group has him exploring familiar works against a background of voices, and, more important, with two of his fellow first-generation boppers, the pianist Bud Powell and the drummer Kenny Clarke.

Two albums from 1962, “New Wave!” and “Dizzy On The Riviera,” feature a tad too many bossa novas (it’s hard to wade through a whole album of that material, even when it’s essayed by Gillespie), but there are compensating virtues in the final two projects of the set, both of which are film-oriented. “Dizzy Goes Hollywood” is a pop project consisting of 12 movie themes that could have been little more than a piffle, but these familiar melodies (including such ethnic diversions as “Exodus,” “Never on Sunday,” and “Lawrence Of Arabia”) are wittily arranged for quintet by the resourceful Billy Byers and played with suitable verve by the front line of Gillespie and Mr. Moody.

The last 12 tracks, written by the pianist Mal Waldron for the soundtrack of the independent production “The Cool World,” amount to a fascinating suite for Dizzy and quintet. Brooding and introspective, these compositions are a counterpoint to the frothy material the same group played on the “Hollywood” album, yet both bring out the best in the Gillespie/Moody/Kenny Barron group.

Thus, the man who did as much as anyone to help spawn bebop and modern jazz continued to find new and interesting directions to explore in his music 20 years later — and even 20 and 30 years after that. Indeed, all of the music here bears out the opinion of Miles Davis, who once said, “Whenever I want to hear something new, I listen to Dizzy.”

wfriedwald@nysun.com