In the last Jazznicity column, I focused on meat-and-potatoes big bands in Tokyo. But in addition to those bands that work directly in the jazz tradition, there are many others seeking to extend its range of possibilities.

In traditional big bands, the trumpet, trombone, saxophone and rhythm sections all work together toward a smooth, harmonious unity. Energy and soloing are important, but only if it sounds good. These new big bands, however, don't shy away from dissonance or disruption. They bring in fresh sounds, styles and structures to intentionally create musical tensions. By drawing on free jazz, blues, funk, Caribbean, classical or art music, these big band innovators create a sound that may not be as pretty but is often more interesting.

Well-known jazz trumpeter Tomonao Hara and pianist Yuki Arimasa created the Siena Brass Fantasy to experiment with a mixture of jazz and classical techniques. They combine carefully composed charts, horn players culled from classical orchestras and a jazz rhythm section. This musical hybrid often goes under the name third-stream jazz, and the music, which trades jazz swing for classical harmonies, is lush and orchestral. There is still room for improvisation, but the quality of musicianship is the real pull here. The musicians' control and nuanced reading of the compositions makes for an elegant, unjazzlike sound.

At the other end of the spectrum is the Shibusa Shirazu Orchestra, a wild, funky collective that takes spontaneity as its ordering, or rather disordering, principle. Their music is scarcely written, much less rehearsed, instead developing organically within their performances. With a few key-ins and hand gestures by leader Daisuke Fuwa, the various members interact with each other over strong rhythmic grooves.

The roster of performers can number up to 30, though it's hard to count since they're often marching through the crowd or disappearing backstage to change costumes. The orchestra's CDs capture their sound well but not the entirety of their carnivalesque impact. They are best heard live, and besides you can't see the naked butoh dancers on audio CDs . . .

In between those two extremes are big bands like pianist Tom Pierson's. Pierson writes highly original music that blends dissimilar sounds and rhythms. To his jazz base, he adds touches of fusion, samba and what might best be described as tone poems. The pieces are influenced by free jazz but are never limited by that. His compositions have a complexity to them that forces even the band members to really concentrate (often during performances you can see them asking the player next to them for directions mid-song). But the unusual patterns and unexpected juxtapositions are also clearly energizing so that solos from everyone in the band really explode.

All the while, Pierson races back and forth from whaling away on the piano to manically conducting center-stage (in stark contrast to his work with his other group -- a calm, reflective piano trio). Pierson's big band performs all too rarely but is slated to record later this year.

Another progressive big band is the Satoko Fujii Orchestra. The diminutive leader's appearance belies her ferocious playing. Fujii and trumpeter Natsuki Tamura (her husband and co-leader) returned to Tokyo last year after living and playing for years in the United States, where their progressive duets and quartets received wide critical acclaim. Their Tokyo big band gives them a larger palette to play with. As a soloist, Fujii throws off notes like Jackson Pollock threw paint, while encouraging the other players to do the same. Her pieces are a swirl of dreamlike spoken narratives, mysterious chanting, squealing saxes and razor-sharp trumpeting. Fujii and Tamura take turns waving their soloists onto greater wildness or cutting in to totally rechannel a song. The band members often seem as surprised as everyone in the audience, which is probably just what Fujii wants. It's not always clear where the band is going, but it's great when they get there.

Less experimental, but equally eclectic in their mix of sounds are three young groups that pack in listeners -- and dancers. The 923 (ku-ni-san) Band, led by Mutsukuni Kohata, plays upbeat bop and blues. The band is polished enough to perform a tricky Stan Kenton number, but soulful enough for slow, gritty blues. They have a rustic swing that oddly resembles the "territory" bands that roamed the U.S. South and West in the swing era. Kohata doubles on trumpet and guitar, leading the band with a bear-like stance beneath his blonde mohawk.

The T.P.O. Funk Orchestra has a powerful engine inside its super-tight rhythm section. They have a loyal following who like to vote on the most handsome band member of the evening. Most fans would agree that it's a tough call. But, their ability to lay down funky rhythms and dynamite solos is very much on par with their looks.

Shiro Sasaki also keeps a youthful feel to his groups. Having played with the popular salsa band Orquesta de la Luz, he is comfortable directing his 16-piece band in blending together elements of reggae, salsa and Caribbean music. At one gig, the band (the name has changed a couple times recently) filled nearly half the dance floor, but everyone just kept moving -- in and around the front line's music stands -- just the same.

These younger bands, ironically, are in some ways the most traditional. After all, the original purpose of big bands was to pump out good-time dance music. These bands show that there is already another generation of players immersed in the creation of a large, loud sound. And the regularly packed jazz clubs show that plenty of listeners share that fascination.