Thomas Wolfe told us that “only the dead know Brooklyn.” Lighten up, dude! I will admit that when I was growing up there, Brooklyn always seemed like a great place from which to escape. Now, however, there’s the Brooklyn Jazz Underground, a collective of 10 enterprising instrumentalist-composer-bandleaders who are transforming that boroughsinto first base for exciting new music.

The Brooklyn Jazz Underground (www.brooklynjazz.org) has spared me the ordeal of crossing that bridge by producing its second annual festival at the club Smalls, off Sheridan Square in the West Village. Between Thursday and Saturday, the BJU presented nine of its 10 bands, of which I caught five. Rather than being set up like a sampler, like the Vision Festival or presentations of new jazz at the Knitting Factory, these were full, two-hour mini-concerts, presented in the newly congenialized atmosphere of Smalls, a cozy room full of bright young 20-somethings who look like they could have just walked off a MySpace page (and a far cry from the foreboding dump it was a decade ago).

For me, the leading figures in the BJU are the Ferber twins — trombonist Alan and drummer Mark — who together and separately played in three of the five shows I heard. Alan Ferber’s Nonet was the most appealing ensemble of the entire enterprise: It comes straight out of the 60-year history of mid-size bands in modern jazz, including the original Birth of the Cool band and subsequent ensembles led by Gil Evans and Lee Konitz. The group excels at making music that sounds new yet firmly grounded in tradition. The music has its feet in the foundation of modern jazz but its head in the clouds, a kind of bebop without boundaries.

The Nonet, which played the 10 p.m. set on Thursday night, has also just released its second album, “The Compass” (Fresh Sound). Unlike other contemporary mid-size groups (such as Joe Lovano’s nonet), the writing is largely sectional — you will, for instance, hear all three saxophones playing as a unit, as you would in a big band. As with the other BJU groups, Alan Ferber made the larger context as important as the individual solos, thinking about the details and the big picture at once. In addition to music from “The Compass,” Mr. Ferber also offered “Union Blues,” a fresh reworking of basic blues elements, and an imaginative recasting of Gigi Gryce’s bop classic “Reunion.”

The other four groups I heard were quartets, none of which, coincidentally, employed a pianist, and both of Friday night’s bands were led by tenor saxophonists. First was the Dan Pratt Organ Quartet, which featured both Ferbers as well as Jared Gold on electric organ. Even with an organ at the center of the action, the music was more like bop than soul jazz; on a fast and funky number such as “Uncle Underpants,” the combination of a tenor and a trombone in the frontline playing tricky meters brought to mind the original Jazz Crusaders and their 7/4 “Song of India.” The group’s one standard and sole ballad was “Star-Crossed Lovers,” with the two horns in counterpoint; Messrs. Pratt and Ferber divvied up Billy Strayhorn’s exquisite melody, but the boldest move of the arrangement was to give the featured solo to Mr. Gold’s organ in a medium-tempo interlude at the center.

The BJU seems to have a fondness for saxophone-guitar front-lines: Next on Friday was Jerome Sabbagh, whose career has led him from Paris to Brooklyn (you’d think it would be the other way around), working with Ben Monder on guitar, Gary Wang on bass, and Ted Poor on drums. Mr. Sabbagh’s tenor timbre was just as pleasing as when i heard it the previous Saturday at the knitting Factory. Unfortunately, he spent a long time on two Middle-Eastern-style instrumentals on soprano sax. His soprano isn’t nearly as sonically soothing as the tenor (no one’s is), and these numbers gave Mr. Monder an opportunity to unleash his busy soundscape interludes, in which he uses the guitar to produce a backdrop of electronic noises that have seemingly little to do with notes or harmonies. I grew impatient waiting for Mr. Sabbagh to take out his tenor again, and i was relieved when he did.

Saturday’s bands featured the alto saxophonist Loren Stillman playing against a guitar. He first performed as part of Barcelonan bassist Alexis Cuadrado’s Puzzles Quartet, with Mark Ferber on drums and Brad Shepik on guitar. (Mr. Cuadrado plays bass with the Ferber Nonet, and both brothers play on his new album “Puzzles.”) Mr. Cuadrado’s compositions are solidly melodic, and he devises lots of resourceful ways for the alto and the guitar to fit together as if in a jigsaw puzzle: harmony, counterpoint, unison, conjoined solos, and trades. at various points you’d swear you were hearing a trumpet-sax front-line, or a group with some sort of brass in it, just from the sheer ingenuity of Mr. Cuadrado’s small-group writing. He stresses arrangements and interplay rather than long solos, and he keeps tracks to respectably short lengths so that your attention rarely wanders.

Mr. Cuadrado’s tunes, by turns, sound either like jazz standards or pop-ish hooks. this was quite different from the final group, Bad Touch (not to be confused with the Bad Plus), led by Mr. Poor, even though it also featured Mr. Stillman on alto, this time playing opposite Nate Radley on guitar. Bad Touch was the most avant-garde of the five bands I heard. the group employs less in the way of conventional melody; rather, each of the four players seemed to be putting down short patterns, snippets, fragments, and cells of tunes, which at times interlocked with one another and at other points flew off in separate directions; using an organ in this context brought mental images of an ice rink in which all the skaters were drunk.

Who knew so much interesting music was being produced in that most maligned of boroughs? To paraphrase President Kennedy (who liked jazz but probably never went to Brooklyn), “Ich bin ein Brooklyner” — we are all Brooklyners.

wfriedwald@nysun.com