Detroit has left an indelible mark on American music. The name evokes pivotal figures in the history of soul (Motown), rock (The Stooges, MC5), white rap/tabloid fodder (Eminem, Kid Rock), and bigoted right-wing cock-rockers brandishing crossbows.

But when it comes to jazz, Detroit's importance isn't as immediately recognizable.

SIDEWAYS: "I am always trying to stay in balance with the intention of the composer or bandleader, remaining in service for the greater good."

The Motor City's jazz legacy shares one noticeable and, to locals, regrettable feature with our own: Its favorite sons and daughters all tend to skip town to find fame and (less often) fortune elsewhere. But where Philly expats, no matter how long removed, tend to have a discernible sound (or at least attitude), Detroit can boast no such homogeneity, mainly due to the fact that it generates sidemen more than leaders. The Jones brothers, Donald Byrd, Yusef Lateef, Kenny Burrell, Paul Chambers, Tommy Flanagan: While most are not among the first rank of innovators, their inspired accompaniment has been indispensable to the greats for whom they worked.

Geri Allen will be representing Detroit as part of the Kimmel's "One Nation Under Jazz" series, with her own quartet and special guest Ravi Coltrane. If Detroit's contribution to jazz history is destined to be first-rank hired hands, then Allen has done her hometown more than proud. While the pianist is a distinguished leader in her own right, recordings under her own name are few and far between. Her latest CD, 2004's The Life of a Song (Telarc), ended a six-year dry spell.

The long wait between releases, however, has been lessened by Allen's busy schedule as a sideperson, a role that in her case doesn't come across as subservient to her own music. Allen is a chameleon, most closely akin to Herbie Hancock in the diversity and adaptability of her playing. But where Hancock continually flirts with the pop world, most recently suffering under the delusion that he's Carlos Santana and jamming with the likes of Christina Aguilera, Allen is content with the range of possibility presented by the myriad forms of jazz. She is less an accompanist than a medium, channeling the leader's intent and internalizing it. Like a method actor, she becomes the emotion she plays, always expressing herself while remaining true to the composition.

That aspect has been manifest most clearly in the past few years through her work with saxophonist Charles Lloyd. A spiritual explorer on the order of John Coltrane, Lloyd, in his own compositions as well as his choice of standards, creates intensely individual statements almost too personal to allow anyone else inside. Yet while the trajectory of the journey is always his, Allen's contributions never seem like the mere interjections of a fellow traveler. Allen credits Lloyd's willingness to seek out "like-minded artists and [allow] them to feel invested in the experience." She compares his methods to those of famously improvisatory filmmaker Robert Altman, who directed her in the film Kansas City.

The individuality of Allen's playing is evidenced also by the fact that she was selected by Ornette Coleman, whose first act of stylistic provocation was tossing the piano out of the jazz quartet and who has rarely looked back since, for his Sound Museum project in the mid-1990s, recording two albums of identical material with different interpretations. Allen, who has always straddled the line between traditional and free playing, responds to Coleman's harmolodics with dense cascades of sound that tumble around the altoist's eel-slippery lines in shifting clusters, and finds more melodic undertones in Coleman's loose-limbed compositions than perhaps anyone else he has played with.

Allen's own pieces often feel like suggestions rather than full-blown compositions, mere hints that only become fleshed-out with further elaboration. In practice, this plays to the pianist's strengths, allowing her to create pensive mood pieces as she works through the implications of her still-coalescing melodies. Fittingly, Allen sees the difference between accompanying and leading as one of degree, not of kind.

"When I am working as a sideperson, I am always trying to stay in balance with the intention of the composer or bandleader, remaining in service for the greater good. I try to get out of the way of the flow, so that only pure intention remains. As the bandleader, my goal remains the same; however, the direction is more personal and self-defined."

Fortunately, the wait between releases won't be so long this time. Allen enters the studio next month with veterans Ron Carter and Jimmy Cobb, and has been commissioned to compose a work in tribute to the survivors and victims of 9/11.

"Music is an undeniable force for healing, and can truly change lives for the better. I hope we as a culture will recall the time when live jazz was as close to us personally as the neighborhoods we lived in. Today's musical challenge is to reconnect. If we all keep reaching out our hands, we will finally touch each other again."

Geri Allen with Ravi Coltrane, Sat., Feb. 11, 7:30 p.m., $36-$41, Perelman Theater, Kimmel Center, 300 S. Broad St., 215-893-1999, www.kimmelcenter.org.