Count Basie defied F. Scott Fitzgerald’s famous pronouncement about there being “no second acts in American lives.” Like many big band leaders, he struggled after the war years. But unlike most, he came back and eventually formed a new band as well loved – and long-lasting – as any.

Among jazz aficionados, the two bands are referred to as the Old Testament – known as a group of soloists that downplayed ensemble work – and the New Testament, an arranger’s band in which the soloists were less important. But this isn’t quite accurate: The original Basie band, as Loren Schoenberg has pointed out, featured some of the most brilliant jazz orchestrations ever written, and the later group boasted many of the most amazing improvisers of the modern era.

A new eight-disc reissue, “The Complete Clef/Verve Count Basie Fifties Studio Recordings” (Mosaic MD8-229), shows that the transformation Basie and his new band underwent was subtle and gradual. When the box begins, in 1951, the Count (1904-84) had just reunited his band for a one-shot tour with the singer Billy Eckstine. This group sounded much more like the rough-and-ready edition of the 1940s than the slick machine of the 1960s.

That’s partly because many of the players were the same. The rhythm section of Basie, guitarist Freddie Green, and drummer Gus Johnson was intact. Several of the early band’s chief arrangers, including Buck Clayton and Buster Harding, were still contributing new works to the library. The Count also maintained his trademark innovation of two contrasting tenor saxophone soloists, though the original team of Lester Young and Herschel Evans had been replaced with Paul “The Vice-Pres” Quinichette and Eddie “Lockjaw” Davis.

By 1953, the latter two would be followed by Frank Wess and Frank Foster, who along with singer Joe Williams would help define the 1950s version of the Basie band. Mr. Foster told me about a decade ago that he was first inspired to join Basie when he heard Neal Hefti’s “Plymouth Rock” (“I just fell in love with that,” he said), but that when he came on board, he realized he liked the writing of saxophonist Ernie Wilkins even better. Mr. Hefti and pianist Nat Pierce (like Mr. Hefti, a veteran of Woody Herman’s great bands of the 1940s) had been the first arrangers to join the new Basie lineup, and along with Mr. Wilkins they set the band well on its way to employing one of the great arranging staffs in jazz history.

The arrangers made particularly good use of Mr. Wess and Mr. Foster, who themselves became fine arrangers in due course. Mr. Wess has often spoken of how he idolized Lester Young – how he, as a student musician in the early 1940s, waited for the Basie band to travel through Washington, D.C., so he could go backstage and salute the “Prez.” But Basie didn’t for his new saxophonists into the roles of Young and Evans. Both Franks were part of the newer bebop movement, influenced as much by the more aggressive, bigger-toned Evans/Coleman Hawkins school as they were by the lighter playing of Young.

Mr. Wess and Mr. Foster demonstrated their combination of competition and cooperation in “Two Franks,” a brilliant arrangement done for the two-tenor team by Mr. Hefti. They play together, in dazzling unison, in an intricate, tricky line that would be impressive even when played correctly by a single saxophonist. They improvise off each other, exchanging phrases written into the chart and adlibbing others. It isn’t that you can’t tell Mr. Wess from Mr. Foster, but, as in the old Young and Evans days, the distinction is no longer important.

Around the same time, Mr. Hefti also wrote “Two for the Blues” as another tandem tenor outing for the two Franks, this one slower and bluesier. The use of vibrato doesn’t always work in a reed section, but here the tenors match their tones and timbres perfectly.

Mr. Wess would also make his mark with the flute: Solos with Basie on “Flute Juice,” “Perdido,” and elsewhere gave a new instrumental sound not just to the band, but to the whole of jazz. Thanks largely to Mr. Wess, the flute would join the soprano saxophone as a successor to the clarinet in the postwar period. That new role is clearly illustrated on Mr. Wilkins’s masterful “Trick or Treat” arrangement. This is essentially just Mr. Wess playing the blues on flute for three minutes, but it boasts all sorts of unexpected twists and turns.

Mr. Wilkins was also the perfect arranger to help Basie introduce his new singer. Williams had been scuffling across the band scene for some 15 years when he joined the Count. But the brilliant leadership of Basie and the inspired charts of Mr. Wilkins and Mr. Foster made him a star. In “Every Day I Have the Blues,” Williams and Mr. Wilkins dazzlingly elaborate on a rudimentary theme by Memphis Slim. This would join “April In Paris” as the most recognizable Basie classics of the era.

At the same session as “Every Day,” Mr. Foster arranged another great Memphis Slim tune for Basie and Williams. It was called “The Comeback,” and could have served as the theme song for the revitalized Count Basie Orchestra.

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The new Mosaic Basie box also features an interesting array of guest stars sitting in with the band: Oscar Peterson, Buddy Rich, Al Hibbler, and Ella Fitzgerald. But the biggest surprise for me is a 1954 date in which Bill Hughes, the trombonist who had joined the band only a few months earlier, replaces Basie at the piano. Fifty-one years later, Mr. Hughes is still in the band, and will lead the Count’s old outfit at Birdland this weekend.

In the 1950s, Birdland was Basie’s home base, and this weekend’s performance, in which the current Basie aggregate plays in the current Birdland, could technically be regarded as a ghost band playing in a ghost club. Yet after a few blasts of Butch Miles’s powerful, Buddy Rich-style drumming, it will surely be obvious no one is about to give up the ghost.

The Count Basie Orchestra performs tonight through Saturday at 9 & 11 p.m. at Birdland (315 W. 44th Street, between Eighth and Ninth Avenues, 212-581-3080, $40).