A "zooid" is a cell that can move independently within a larger organism — making it the ideal moniker for Henry Threadgill's fascinating quintet.

Three years ago, Threadgill became only the third jazz composer to win the Pulitzer Prize for Zooid's "In for a Penny, In for a Pound," a 79-minute suite that includes a concerto-like piece for each of his bandmates.

This weekend the group will provide the capstone performance for "Celebrating Henry," a mini-festival at Walker Art Center in Minneapolis. It starts Friday, with two dozen local artists marking Threadgill's 75th birthday by interpreting works from throughout his career. Zooid will perform Saturday along with the jazz power trio Harriet Tubman, comprising alumni from his previous bands.

That is a formidable list. The Chicago-born, New York-based saxophonist has beguiled audiences since the 1970s, when his trio, Air, would cruise from beautifully ethereal "free jazz" into wonderfully deconstructed ragtime music.

The '80s were devoted to his seven-piece Sextett, which deployed a cellist as a locus point between various brass and percussion instruments. In the '90s, he gave us Very Very Circus, appropriately topped off by a pair of tubas.

Around the turn of the century, Threadgill devised a new method of composing that asked musicians to improvise within blocks of three notes assigned to each member, creating spontaneous melodic changes and counterpoints to layered rhythms that he set forth. Zooid workshopped the concept for an entire year before performing and recording.

During a recent phone conversation from his New York home, Threadgill was as effervescent, engaged and generous with his time as one might only hope from someone frequently called a genius. The interview has been edited for length and clarity.

Q: How has Zooid evolved over the nearly 20 years it's been together?

A: Well, individual players have gone beyond, made these into journeys I had no way to anticipate. You know, you look up in the sky through a telescope and you see a planet. You spend all your time training, developing and devising your attempts to get there. But you don't know what's there until you get deeper. That discovery is the most important thing, the greatest thing.

Q: You have consistently praised the members of Zooid for their commitment.

A: Oh, yeah. But you know, everything we have in life is done that way, where people labored and stayed for something, with the fortitude necessary to develop it. What has been amazing is that I am still discovering all kinds of routes through this approach that I have found.

Q: You extensively use instruments like the cello and the tuba, which are not typically featured alongside each other. How did you come upon that — just personal preference?

A: Personal preference and the way that you hear things. The cello, like the clarinet, has incredible range. You can pair it with anything.

Q: Another distinctive thing about your music is that there is a spaciousness to it, a diaphanous quality.

A: I put in enough space because it puts things into perspective. Silence has to be in the picture from the very beginning. Because that's what music is: organized sound and silence.

Q: Also notable is the use of humor in your music. You frequently inject what seem like deliberately delightful surprises into your pieces.

A: You should never take yourself too seriously. You have to be a realist and keep that up on the table. Because life is about so many different things. I try to make sure that I am getting my entire experience in there, and some of that is: I am happy.

Q: Speaking of experience, your bio includes working in church bands, serving in Vietnam, being on the ground floor of the AACM jazz revolution in Chicago, residency in many different countries and this whole new approach with Zooid. Through all that, have there been things you regard as touchstones in your creative development?

A: Oh, I think so. You always come upon things in life that serve you — mottos and ethics and books and art, things you can keep going back to.

I am always looking to see how different people express art, how art is expressed. So I could go back and listen to Pavarotti, I could listen to Martin Luther King, when you hear how he delivered a message. It is always good to hear great speakers because it is like listening to music. The pacing, the context, the emphasis, the rise and fall, the inflections. And it is the same with painting or photography. I have photographers and books I love, and filmmakers. I love Alfred Hitchcock.

Q: He was a guy who used silence in his own way.

A: Yeah. And gave actors a lot of room to improvise.

Q: Growing up on the south side of Chicago when you did seems like an especially good time for an artist.

A: It was one of the most fertile periods in all of music and art that I could think of. [Conductor/composer] Fritz Reiner had the Chicago Symphony Center on fire. Chicago was in the vanguard of the theater world and the dance world. Charlie Parker came in and out of Chicago, and all the blues people were there. It was the center of gospel music. I couldn't have been in a better place.

I can remember everything because of music and sound, back to when I was 2 years old. I'd hear the streetcar coming down Cottage Grove and stopping at 33rd Street and I heard that carriage bell made out of copper filled with silver, and I would run to the window, and see a parade of all different people going to work. And then the radio would come on. Arthur Godfrey is on the radio. Art Linkletter has got a band, with an accordion player in it.

Sounds always attracted me. My father had a big record collection, and my mother took me to see all kinds of live music from the time I was 3. We'd see all the big concerts — Louie Jordan, Count Basie.

Q: When did you develop a need to compose music?

A: It felt like I always wanted to know how music was made. When I was about 4, I began teaching myself how to play the piano because players like Albert Ammons and Meade Lux Lewis were coming on the radio every day playing boogie woogie. I'd sit at the piano and try to figure it out.

I remember I was very frustrated because my hands were so small, trying to play those boogie woogie lines with my left hand. And then I would do it when [composer Sergei] Rachmaninoff would come on.

By the time I was finishing high school, I knew I had to [write and play] music.

Q: You had to derail that to serve in Vietnam. Then, of course, it isn't easy to acquire the level of independence and respect necessary to follow your own vision as a composer.

A: Everybody is not made to do this, or supposed to do this. Just like everybody is not supposed to educate our children or be a doctor, or sew buttons on a shirt. I think it is important we find the place in life where we fit, where we are happy without complaint.

Q: At the end of a long interview you did for the Library of Congress, the interviewer asked you to define success. You said it was knowing what you want to do and then doing it. You pretty much get to write what you want and work with an ensemble devoted to your work. Your ideas keep coming. Life is really good for you now, isn't it?

A: Yes, I would say so. It is a long journey getting to this point. But it is not just physical circumstances. It is a place in your head, too, that you have to arrive at.

Gratitude is most definitely part of it.

Britt Robson is a Minneapolis-based journalist and critic.