The Yellowjackets Buzz From One Style to Another : Jazz: Popular band, appearing Thursday at the Coach House, credits changes to growth, not an identity crisis.

The Yellowjackets have an identity crisis. Well . . . not exactly a crisis--more like a minor confusion.

In the last few years, the popular four-piece band--which appears at the Coach House in San Juan Capistrano on Thursday--has won Grammy awards in the rhythm-and-blues as well as the jazz fusion categories. Their current album, “The Spin,” is filled with straight-ahead jazz blowing, a marked contrast from the music on “Shades”--music which, despite its Grammy award, was described by bassist Jimmy Haslip as “fusion disco.”

In their earliest years, when the band came into existence as a backup unit for Robben Ford, the sound was guitar- and blues-centered. When Ford left for a solo career after the first two albums, the Yellowjackets’ identity drifted in and out of focus until the addition of saxophonist Marc Russo brought a frothy, pop-jazz feeling to the ensemble.

But the ‘Jackets’ current well-integrated, strongly improvisation-oriented sound didn’t really emerge until drummer William Kennedy replaced Ricky Lawson in 1986.

Perhaps understandably, the players do not exactly revel in retracing the styles that have coursed through the band’s 10-year history.

“I wish we could forget about all the changing personnel and the different labels,” said pianist Russell Ferrante in a conversation last week.

“I’d like to get back to the simple question, ‘Does the music speak to you, does it inspire you, does it do something to you that makes you think about the world or yourself?’ Because when I’m composing, I’m not thinking about categories, or this or that. I’m just concentrating on finding out about what I have inside myself that I really want to express.”

Haslip, however, pointed out that pure self-expression is not always as easy as it seems. “To be perfectly honest about it,” he explained, “being placed in different categories has been useful to us.

“Jazz is not really a popular idiom around the world. People don’t seem to be willing to sit down and listen to it. They think it’s some kind of wild Cecil Taylor record or something. So, in that respect, being known only by that label can be harmful.

“On the other hand, we really do believe in jazz, so it’s a kind of a double-edged sword. You want to be true to the art, you want to come up with something adventurous, but if no one’s going to listen to it, well, then what? Do you continue to pursue some form of music that no one’s interested in, or do you try to perform for the masses?

“It’s a tough question, and it’s one that we deal with every time we go into the studio. Usually what wins out is that we’re true to the art. We just play what we’re honestly feeling and hope that it’ll connect with a large audience. So far, at least, we’ve been pretty lucky at doing just that.”

Despite his distaste for categories, Ferrante acknowledged that the group has made a strong evolutionary change in the last few years.

“There’s no doubt that the music has gotten more improvisationally focused and more rhythmically elastic, especially since since William Kennedy joined the band on drums--and that’s for the last three albums. And a good part of that has been the move toward a more acoustic sound on the current album.”

Interestingly, the music on “The Spin” was initially conceived with the thought of having the Yellowjackets record with producer-arranger Claus Ogermann. “We were really thinking of placing the band in an orchestral setting,” Ferrante said, “but Ogermann’s schedule was too busy and things didn’t work out, at least not this time. But I think the acoustic sound of the album really was influenced by the thought of working with a large orchestra.”

As the Yellowjackets approach the end of their current tour, the prospect of making a new recording looms on the horizon. And with it, once again, the old, nagging question of musical identity.

Haslip viewed the problem with characteristic directness: “Hey, we’ll write the music, perform it to our best ability, play it from the heart as honestly as we can, and that’s about all we can do.”

Ferrante, the Yellowjackets’ primary composer, took a somewhat more pensive pint of view. “Well, at the end of the tour,” he said, “I guess we’ll all just collapse for a while, and then start writing again. Every time we’ve done that, I’ve been amazed at how new things start bubbling up, and how there’s just no telling what will come up next.

“But that’s what feels right to me, and maybe that’s why there’ve been so many changes and so many categories. Maybe the real identity of the Yellowjackets simply comes from our desire to see where the music will take us.”

The Yellowjackets will play Thursday at 8 p.m. at the Coach House, 33157 Camino Capistrano, San Juan Capistrano. Tickets: $19.50. Information: (714) 496-8930.