Since their 1980 self-titled debut, the Yellowjackets have conjured numerous enigmatic recording feats, continually evolving over a 13-album career. Blue Hats is an impressive addition to the quartet's lineage of collective improvisation, offering nine straight-forward originals that uniquely deploy inventive melodies, complex harmonies and shifting, unorthodox rhythms. They are truly a modern jazz quartet for the '90s.

"This particular album got its start when we rented a rehearsal space for two weeks prior to the recording and just jammed," Haslip explains. "This is the first time we ever approached writing in this way for a project. We didn't bring a lot of preconceived material into these sessions. We jammed, found some nice sparks which became the seeds for compositional ideas, and then compiled those ideas into developed pieces."

Ferrante says, "When something promising emerged from the sessions, I'd turn on the DAT tape recorder and let it run for three-to-five minutes. I catalogued all the ideas. Then we considered the most promising material for creating the compositions we wanted to record."

"This was a unique experience for us," adds Kennedy. "Sometimes when you use a lot of studio technology like electronic sequencers, you miss out on that live performance aspect."

As a result, Blue Hats showcases the quartet cutting loose and engaging in an abundance of solo improvisations. "It's not overproduced," Haslip notes. "We didn't invite any guests and we didn't need any overdubs. Because we jammed so much, we had already come up with these great parts that fit together naturally."

A key factor in the success of Blue Hats is the Yellowjackets' longevity as a band. Kennedy joined the group in 1986 and Mintzer came on board in 1990. "We know each other so well musically and personally," Kennedy says. "That's what gave us the freedom to work together creatively on this project. We're familiar with each other and we trust each other."

Ferrante adds that the diversity of musical interests each member brought to the project, which features the Yellowjackets in acoustic and electric settings, also enhanced its outcome. "All of us have broad musical tastes. No one's a purist. We're all open to pulling from acoustic and electric jazz, classical music and funk. That's what makes us so different from most jazz bands. We rebel at the idea of being categorized. Some people want to believe that acoustic jazz represents the real jazz tradition. But we feel that jazz is made richer as it takes on different musical influences."

The Yellowjackets got its start as a "rhythm and jazz" group when Ferrante and Haslip backed guitarist Robben Ford on one of his albums. That project evolved into the band. After Ford left the Yellowjackets in 1983 to pursue his solo career, alto saxophonist Marc Russo replaced him and the band began to explore more jazz-oriented material. With Kennedy joining the group in 1986, the Yellowjackets stretched into a more adventurous jazz zone buoyed by African, Brazilian and world music rhythms. When Mintzer took Russo's place in 1990, the Yellowjackets upped the jazz ante even further with his swing and big band contributions.

Special guest producers and collaborating artists have also played valuable roles in the evolution of the distinctive Yellowjackets sound. On the band's 1989 album The Spin, Norwegian producer Jan Erik Kongshaug (ECM Records) introduced a sparse and contemplative feel. The follow-up, Greenhouse, once again featured Kongshaug and percussionist Alex Acuna, plus arrangements by Vince Mendoza. The acclaimed arranger has also collaborated with the Jackets and the German WDR Big Band, and the 50-year-old Dutch Metropole Orchestra. The Yellowjackets' last album, Dreamland, featured vocalist Bobby McFerrin.

In addition to the Yellowjackets' commercial successes, the group won Grammy Awards in 1986 (Best R&B Instrumental Recording for "And You Know That" from the Shades album) and 1988 (Best Jazz Fusion Performance for the Politics album). Last year the band received its ninth Grammy nomination for Dreamland, its first Warner Bros. release since returning to the label's roster after an absence of ten years.

The Yellowjackets continue to tour the globe, discovering new markets, reaping the plaudits of international audiences and garnering new fans.

Track by track overview of Blue Hats:

The album opens with "Capetown," a smooth, melodic number with a funky polyrhythmic groove and ecstatic tenor sax-blowing by Mintzer. Kennedy based the original jam on an unusual rhythm passed on to him from an African friend living in Los Angeles. "It's a quirky beat in the 6/8 African tradition. It was difficult to play and feel at first. But it didn't take long for Russell and me to fall into it."

Ferrante adds, "While Will was working on the rhythms, I was playing around with folk-like melodies on the piano. On the bridge I was also using some denser harmonic schemes I'd been experimenting with, such as different chord voicings and intervals in contrary motion. That same kind of harmony also shows up on 'Coal Minor's Blues.' Usually in the course of putting together an album, there will be harmonic or melodic discoveries we each make on our instruments that we try to weave in."

"With These Hands," a soulful, gently swinging tune, showcases more tenor sax gusto, charged acoustic piano runs and Haslip's striking electric bass solo. Ferrante explains that the piece was the band's attempt at coming up with a major-key tune in an African/island groove. "There's also that contrary motion in the introduction and the chorus section." Kennedy adds, "When you listen to the song, it's one of those that may not come across as musically complicated. It has a relatively simple groove and a melody that you can almost sing. It's nice to get a tune like this on the album."

The alluring ballad "Prayer for Peace" is one of two tunes that Mintzer sent on a tape for the rest of the group to consider before he made the trip from New York to Los Angeles. Initially he had recorded the piece with the Metropole Orchestra and revisited it in a quartet setting on his last solo album. Ferrante notes, "Bob had hopes of incorporating string and horn arrangements, but it sounded so full and complete with just the four of us that we decided not to do any overdubbing."

The catchy "Statue of Liberty" smokes with Ferrante's aggressive and fleet piano lines and Mintzer's soaring bass clarinet solos. "It's a blues," Ferrante explains. "I had experimented with this piece before, but it never made it onto one of our albums. We enjoy playing this. The twist was having Bob play the bass clarinet. It's perfect for the number." Haslip, who notes that there's a surprise in the bridge, adds, "I gave the tune its title because of that. It's like that old football play called the Statue of Liberty where a running back grabs the ball from the quarterback who looks like he's ready to throw it."

The melancholy "Coal Minor Blues" is next. Influenced by John Coltrane and colored by dark instrumental hues (hence the double meaning of "coal" in the title), Ferrante notes that the piece fit the concept of the album perfectly. "It's simple and open and doesn't need any overdubs." Kennedy adds, "This tune shows how open-minded we are to all styles of music. We get our inspiration from a variety of sources."

The upbeat, synth-colored "Savanna," another tune inspired by an African beat Kennedy learned from his friend Paul Tchunga, also developed in one of the rehearsal jams. Haslip set the groove on bass, and Ferrante and Kennedy explored various harmonic and melodic ideas. Mintzer refined the phrasings by sculpting soprano saxophone lines into the mix. "This was a real group effort," Kennedy says. "It's like a journey. We played it with the idea of going for a ride." Haslip adds, "We titled it 'Savanna' because we imagined the journey taking us to the plains in Africa. In my mind we were going on a safari."

"New Rochelle," the funkiest and most radio-friendly tune of the collection, is the other composition Mintzer contributed. "Doing a tune like this is what attracts me to being in the Yellowjackets," explains Mintzer, who plays EWI on the piece named for the New York town he grew up in. "We're not a traditional swing band. Neither are we a traditional funk group. We're somewhere in the middle, bringing both elements together in a cohesive way."

The quiet piano-led "Coquimbo," tinged with a Latin music groove, was an unfinished composition that Kennedy had presented to the rest of the group four years ago. It was pulled out for the jam sessions and worked into its finished state by the band. Ferrante says, "It was the right time for this tune to come to bat again." Haslip agrees and adds, "No wine is ready before its time."

The finale is the beautiful ballad "Angelina," a romantic and introspective piece that Haslip had originally sketched out when he and Ferrante were working on a Michael Franks recording. "I was sitting at a piano and playing chords," Haslip recalls. "I scribbled the chord changes down on a scrap of paper and stuck it in my pocket. When we were doing our jam sessions preparing for Blue Hats, I pulled out the chords and we all nudged them around till we came up with this melody. We were looking for a bona fide ballad, so it worked especially with that big fat tenor sound Bob plays on it."

"This is the real Yellowjackets," says Ferrante in summing up Blue Hats. "This is who we are. Instead of putting on a bunch of make-up or having plastic surgery, we're showing what we can do without elaborate production. Blue Hats is the four of us feeling comfortable with ourselves and each other. It may be less adorned and a little rawer than what people expect from us, but it's more real."