My friend Loren Schoenberg, the lucky so-and-so, somehow got hold of an advance copy of “Thelonious Monk Quartet With John Coltrane at Carnegie Hall” before me. We were standing on 125th Street, around the corner from his office at the Jazz Museum in Harlem, when he popped his iPod headphones in my ears, giving me my first sample of this newly discovered recording from 1957.

What I heard, a section of the song “Epistrophy,” was astonishing. Coltrane begins his improvisation by blasting out a series of dense note clusters, not quite riffs, not quite licks, but brief flurries of ascending notes, each of which rises in pitch within itself before the next batch starts on a higher note. Coltrane plays about a dozen brief variations on this three- or four note mini-phrase before moving to something more like the kind of melody line you’re used to hearing in a jazz solo. As he comes out of the bridge on his last chorus, he plays another variation on the idea, only this time these note clusters – sort of melodic speed bumps – have been smoothed out and fit more gracefully within the flow of the line.

I had never heard John Coltrane – or anyone else – play anything like this before. But I would bet that even before this new CD (Blue Note/Thelonious 35173) is officially released on September 27, I will have heard this phrase, or variations on it, come back at me from dozens of saxophonists. And it won’t be long before every note of this solo is transcribed and memorized by every jazz musician in the world.

This discovery, announced in April, is the second major jazz find of the year (following on the heels of “Dizzy Gillespie and Charlie Parker at Town Hall, June 22, 1945”), and it helps connect one of the missing links of jazz history. The quartet that featured both Monk and Coltrane recorded only three studio tracks together (about 20 minutes’ worth of music), so any newly discovered performance would be big news. But the new concert, which amounts to nine tracks and 51 fantastic minutes of music, is a goldmine.

This is the kind of CD that will immediately start turning up on top-10 lists, not only for 2005 but for all time. In the same way that “Kind of Blue” showcases four giants – Miles Davis, Coltrane, Cannonball Adderley, and Bill Evans – in top form, this is a glimpse of two legends at their best.

In 1957, Coltrane was coming off a two-year tenure with Davis’s quintet. The trumpeter fired Coltrane for missing gigs and being wasted most of the time. Davis had had enough of junkies, having himself come of age in Parker’s quintet and having kicked his own habit only a few years earlier. Coltrane, who spent several months purging his system of drugs (and experiencing a spiritual awakening) after leaving Davis, happened to need a gig at the same time Monk was putting together a new quartet.

Monk had problems of his own; jazz historian Dan Morgenstern believes that the pianist never used hard drugs, but that he had taken a rap for his close friend Bud Powell. In any case, Monk, like Billie Holiday (who sang at this same Carnegie Hall concert),was legally prohibited by New York’s infamous cabaret card law from appearing in nightclubs until early 1957. The pianist had begun working at the Five Spot down on Bowery and 5th Street, and Coltrane joined him in the new Monk Quartet from July to the end of the year. (The only recording of their nightly performances at the Five Spot emerged in 1993, courtesy of Coltrane’s wife; unfortunately, the sound quality is barely listenable.)

The Monk-Coltrane quartet appeared at Carnegie Hall on November 29, 1957, as part of an all-star benefit for the Morningside Community Center. The show also featured Holiday, Ray Charles, Chet Baker with Zoot Sims, Sonny Rollins, and the full Dizzy Gillespie Orchestra. Despite this dream lineup, the Voice of America recording of this concert gathered dust until Library of Congress engineer and jazz scholar Larry Applebaum (who was alerted to its possible existence by Coltrane biographer Lewis Porter) unearthed it earlier this year. The Monk portion is the only set so far announced for commercial issue.

The music is spectacular – not just as good as the sum of its considerable parts, but even better. Both men were feeling liberated by their newfound freedom from drugs and legal shackles – and, more importantly, by each other. There’s a joy in their playing more pronounced than in what they had done and would do separately. For Coltrane, this is the best playing he had yet done on record, with the possible exception of “Blue Train,” recorded that September.

The CD opens with applause being faded up against the first few notes of Monk playing one of his ballads, “Monk’s Mood.” You hear his characteristic juxtaposition of wide-open spaces, mysterious portals to some other dimension of sounds, and those arpeggios and glissandos that sound like a wry parody of a cocktail pianist affecting an exaggerated imitation of Earl Hines or Art Tatum.

Monk’s melody solo is by turns dark and optimistic, heavy and light, stark and opulent – there’s a deep quality about Monk even when he’s enjoying a laugh, but his playing is full of humor even when he’s at its most somber. Just when you think “Monk’s Mood” is going to be an unaccompanied solo, Coltrane comes in; then, just when you think it’s going to be a rubato sax-and-piano duo, the bass (Ahmed Abdul-Malik) and drums (former Basie-ite Shad ow Wilson) enter. But the rhythm section is heard only briefly: The opening track is, in fact, a formal showcase for the undiluted power of Monk and Coltrane together.

In the early nights of the Five Spot engagement, it supposedly took Coltrane a while to catch on to the ways of his leader; this was long before budding jazz students were raised on Monk’s tunes. After four months of working with him, however, Coltrane played these tunes as if he had invented them. The Carnegie Hall concert makes Monk’s other groups suffer by comparison.

Indeed, at this point in Coltrane’s development, he was the perfect side man and collaborator, able to carry out a leader’s ideas and enhance them without taking over. He would do the same for Davis when he rejoined Miles’s group in 1958. On the Carnegie Hall recording, he makes Monk’s music sound more steadfastly Monk-ish than any other of the composer’s collaborators. “Monk’s Mood” is more moody, “Crepuscule With Nellie” is more romantic, “Evidence” more completely justified, “Nutty” nuttier, and the one non-Monk standard, “Sweet and Lovely,” sweeter and lovelier, “Blue Monk” is bluer (with Coltrane piling 10 ingenious 12-bar choruses on top of each other), and “Bye-Ya,” Monk’s ode to calypso, more jaunty in its use of Caribbean rhythms.

There are two versions of “Epistrophy” on the CD, because the full lineup of bands gave two shows that night at 8:30 p.m. and then 12 a.m. (although Monk did not play “‘Round Midnight”). The first version hints at the clusters mentioned above, although Coltrane, more characteristically, solos with the dense style that Ira Gitler would soon describe as “sheets of sound.” The second “Epistrophy” is incomplete, although the whole Coltrane solo is intact. We can be glad that producers Michael Cuscuna and T.S. Monk (the composer’s son, and a respected drummer and bandleader in his own right) included this fragment – and so will saxophonists from now to judgment day.