JAZZ HAS featured prominently in the name of the West Oak Lane Jazz and Arts Festival since its inception in 2004. And as anyone who has attended the annual event can attest, there has been plenty of jazz to be found while roaming the four stages along Ogontz Avenue.

But over the past few years, a glance at the headliners who occupied the prime spots on the festival's main stage would tell a slightly different story. Last year alone, the roster included Teena Marie, the Average White Band, Billy Paul, Tower of Power, War, Jeffrey Osborne, P-Funk - a who's who of '70s-era funk and R&B acts, but it would be a stretch to call any of them "jazz."

"Jazz is hard to define sometimes," said Jack Kitchen, president and CEO of OARC, the nonprofit West Oak Lane community development corporation that produces the festival. "Some people look at War as jazz and other people talk about the Benny Golsons as true jazz, so it's a pretty wide spectrum of artists.

"We really wanted to do jazz from the very first year, but I think you have to build that base of success. The core of the festival has always been the emphasis on jazz and a large proponent of the Philadelphia musicians who perform are true jazz artists, but it is pure jazz this year."

In its seventh year, the West Oak Lane Jazz and Arts Festival will feature a decidedly all-jazz lineup. That's not to imply that the star power will be diminished.

The packed schedule includes singer Al Jarreau with the George Duke Trio; saxophonist David Sanborn swinging the blues with Philly native Joey DeFrancesco; World Saxophone Quartet co-founder Oliver Lake with his organ quartet; and rising star bassist/vocalist Esperanza Spalding.

Warren Oree, artistic director of Lifeline Music Coalition, the festival's music directors, said that the event can now draw crowds on name alone, granting the freedom to stock the roster with jazz musicians who may not have the popular appeal of the funk nostalgia acts. And having fewer people thronging the neighborhood, he suggested, may not be such a bad thing.

"This [jazz] has always been our goal, from the beginning, but we're also realistic and know initially that's not going to bring out hordes of people," Oree said. "But now, that's happening. And last year, the bottle spilled over. When we had Teena Marie the community was inundated with thousands and thousands of people, and it looked like the bottle was getting ready to crack. So we knew that if we made it an all-jazz format, we'd still get good crowds based on the performers, but we're almost certain it's not going to get to the limit like it did last year."

There will also be a bit of added breathing room thanks to the streamlining of the festival from four stages to two. Relish Restaurant, the former site of one of those stages, will host the Jazz Hang Suite, featuring performances by Jeff Bradshaw, Carol Riddick, Jaguar Wright and Norman Connors. The venue will be the first ticketed venue in the festival's otherwise all-free history.

"We want to keep the majority of the festival free, but we have to find a way to self-sustain it," Kitchen said. "That's what we have to do to ensure that we can do this year after year down the road."

The heart of the festival, as it has always been, will be the local artists, Oree's so-called "Philly cats" who comprise the bulk of the lineup.

With fewer stages, Lifeline has jammed the schedule with half-hour sets to accommodate as many acts as possible. Given the notorious punctuality problems of jazz musicians and the tendency for spontaneity with so many of them roaming the festival grounds, that should keep the stage managers on their toes.

Philly is represented this year by, among others, Odean Pope's Saxophone Choir; sax prodigy Dahi Devine; the Landham Brothers, co-led by drummer Byron and saxophonist Robert; and, in one of the headlining spots, Philadelphia native and Coltrane acolyte Sonny Fortune. Oree, whose Arpeggio Jazz Ensemble has been a fixture at the festival, will debut his Freedom Jazz Orchestra, a 16-piece big band packed with local talent.

As this partial list exemplifies, an all-jazz format hardly necessitates a lack of musical diversity.

"Jazz is like a big house with a lot of rooms," Oree said. "I wanted to make sure we kept that variety in mind. Because our previous headliners have been all R&B groups, it was interesting to see what kind of jazz headliner could still generate some kind of interest for a large mass of people the way the Whispers or Teena Marie did.

"Realistically, we know that the volume may not be as intense because that's the nature of this musical beast, but we still knew we could get a nice response from someone like Al Jarreau, who crosses the fence a little bit. And Dave Sanborn, who's considered 'smooth jazz,' which has picked up a large audience, but he's got serious chops. I'm not going to mention any names, but he's not watery like some of them other cats."

As Kitchen emphasized, the goal of the festival is not just to entertain audiences for a weekend, but to promote the West Oak Lane community beyond its own inhabitants.

"Eight years ago, West Oak Lane had a serious vacant housing problem," he said. "We were building restaurants and shops on Ogontz Avenue, but people weren't coming to the shops or restaurants or moving into the community. So the purpose of implementing a festival of this magnitude was that we needed a marketing tool to showcase West Oak Lane and what we were doing."

This year, the festival's reach extends far beyond Philadelphia, through a cross-promotional partnership with New Orleans' Essence Music Festival.

Inspired by that effort, the festival will kick off on Friday with a Mardi Gras parade featuring Camden's U.C.C. Royal Brass Band. Both the Dirty Dozen Brass Band and Preservation Hall Jazz Band will perform during the weekend.