In July 1957, pianist Thelonious Monk, one of the principal architects of the bebop revolution of the 1940s, began to perform with tenor saxophonist John Coltrane at the Five Spot club in New York. They worked together for several months in what would turn out to be one of the most fertile collaborations in the history of jazz.

It was an important time for both of them. Monk was returning to regular nightclub jobs after his "cabaret card," or performer's license, was suspended for six years because of a (probably fraudulent) drug charge. Coltrane himself had kicked drugs earlier that year and was fast developing the mature, powerfully articulated style that would take full flight in the 1960s.

On Nov. 29, 1957, they appeared in a benefit concert at Carnegie Hall, fifth on the bill after Billie Holiday, Dizzy Gillespie, Ray Charles and Chet Baker guesting with the Zoot Sims Quartet. (The most expensive seat in the house was $3.95.) Little was known of that concert until this year, when Library of Congress researcher Larry Appelbaum found a tape, recorded by Voice of America, in the library's archives.

For jazz fans, this discovery is almost like coming across the Holy Grail. Now released on Blue Note, "Thelonious Monk Quartet With John Coltrane at Carnegie Hall" captures the group at its artistic peak, with crystalline sound quality. The quartet appeared in two sets -- the second show didn't start until after midnight -- playing almost exclusively Monk's original tunes.

There are many remarkable things about this recording, not the least of which is the comfort Coltrane and Monk show in working together. At the time, Coltrane was a talented but relatively undistinguished tenor saxophonist who had recently been fired by Miles Davis. In his collaboration with Monk, you can hear the emergence of his titanic sound as he answers the challenge of Monk's quirky harmonies and rhythmic twists.

Another thing about this disc that stands out is that it contains some of the finest and most fully realized piano work that Monk ever recorded. Particularly on "Monk's Mood," "Blue Monk" and "Sweet and Lovely" (the lone standard), he performs with a fluent dexterity rare in his output. Punctuated rhythmic accents give way to Tatumesque arpeggios that feed straight into Monk's spiky melodic ideas. When he supports Coltrane's towering solos, he's not merely laying down a foundation of chords -- he's engaged in a full musical dialogue.

One of the best examples occurs on the opening tune, "Monk's Mood," in which Monk plays an extended solo introduction, with no rhythmic accompaniment. Coltrane quietly enters in an exploratory mood, seeming to discover the plaintive theme almost by chance, as Monk spins out flowing lines that complete the harmonic palette.

On the first of two versions of "Epistrophy," Coltrane integrates Monk's spare melodic architecture with his own muscular style. Behind the saxophone solo, Monk duplicates the melodic line on piano and thickens the harmonic texture. All the while, bassist Ahmed Abdul-Malik maintains a steady walking beat, and drummer Shadow Wilson supplies sharp cymbal work and bass-drum accents that propel the music forward.

The four late-show tunes are more relaxed and expansive than those from the opening set, with more room for solos. (The second version of "Epistrophy" is even better than the first, but it's cut short and stops too soon.) Not only is Monk's piano work crisp and assured throughout, but he guides the quartet with tight, efficient direction. There are no pauses between tunes; the moment the applause begins for one number, Monk is already moving on, playing the opening line of the next.

There's not a single weak link among the nine tracks. This newly found recording captures the eternal fascination of Monk's music: The more you listen to his sometimes unbalanced, eccentric melodies and chords, the more perfect they sound. More than a historically significant artifact, this disc brings a transcendent evening of jazz triumphantly back to life.

The start of something big: From left, John Coltrane, Shadow Wilson and Thelonious Monk at New York's Five Spot cafe in 1957.