Sonny Rollins plays the Fort Stage on Sunday in a set scheduled to begin at 5:45.

Sonny Rollins is one of the last of the remaining giants of postwar American jazz. The saxophonist made his recording debut in 1949 and spent time playing with Miles Davis and Thelonious Monk in the early ’50s before joining a quintet including Max Roach and Clifford Brown, then striking out on his own in 1957, where he’s been ever since.

Sometimes literally.

“I’ve always loved to go solitary places to play,” the 77-year-old Rollins says. He recalls practicing by himself in a closet at age 7, with his mother calling to him to come out and eat. He’s played on the Pacific coast when he lived in California, outdoors on Martha’s Vineyard, and perhaps most famously practiced by himself under the Williamsburg Bridge in New York. “I could make enough music by myself to keep myself interested,” Rollins says, and even a quick listen to his legendary tone and phrasing make the influence obvious.

Rollins started off idolizing jump-blues and R&B master Louis Jordan. He played hard bop for a time and eventually included a melding of jazz with funk and soul. But he sees a common thread in all of it.

“The one particular style of music that I have gravitated to over the years was the kind where there was a fixed beginning, a fixed end, a fixed melody, a fixed harmony. And it was my style of playing to be able to extemporize on those things. And be able to do a lot of free improvisations.”

Rollins, 77, has been playing long enough that almost all of his legendary contemporaries and collaborators — Charlie Parker, Clifford Brown, Max Roach, Thelonious Monk, the list goes on — are “not on the planet now,” as he puts it. But he still feels their presence.

“Their music is still very vital, and they left a lot here, and there’s a lot in their music which I still use. Because when I think about Miles Davis or John Coltrane or Charlie Parker, I channel them, and it’s like they’re playing right next to me. And their musical spirit is still strong within my consciousness. And I’m sure they’re a part of what I do.”

He looks for young bandmates who understand this history and add something to it.

“Each age has its great potential. There are a lot of young people who bring energy to the music, so I respect their youth. But of course when I get people in my band, I look for people who have some historical appreciation for the guys I played with. They don’t have to play exactly like them, of course not. But they should bring a little bit of that to their styles.”

There’s one exception to that, and that’s bassist Bob Cranshaw, who has been with Rollins since the early ’60s.

“Bob Cranshaw was a person I always hired because he maintained the fixed portion of it, and that would allow me to extemporize freely and the song would still be maintained. It was a contrast; if he had the fixed part, then I could go into all of my wild dreams.”

The sabbaticals Rollins has taken over the years have fed his legend. He dropped out of the scene from 1959 to 1961, and again from 1968 to 1971. The first time was the more celebrated one, as he spent a lot of time practicing in the late nights and early mornings on the pedestrian walkway of the Williamsburg Bridge, and titled his 1962 album The Bridge. The difference in his playing and his music wasn’t radical, but he sounded more assured. His second sabbatical included a religious quest that took him to India and Japan.

“I took sabbaticals for several reasons,” Rollins says. Of the first time, he says, “I had no physical place to practice. I’m a city boy — born and grew up in New York City. And blowing a horn in a city apartment is always somewhat problematical. …

“It was musical, but I also kicked my cigarette habit. It was always about making myself a better person. And music coincides with that. So sure, I was practicing and I had some goals in mind — I felt I wasn’t doing my best musically, so I had a chance to work on that. But also, it gave me an opportunity to get within myself and try to improve myself.” He says he doesn’t need to do that anymore. “For one thing, I was able to move out of the city and up to the country,” which made it easier to practice whenever he wanted. “And I sort of gained all I could gain from getting away.” While he’s worked with many instrumentalists over the years, his band does not now and rarely has had a piano player, usually a staple of jazz.

“At the risk of alienating my piano-playing friends — and I’ve played with some great piano players — the piano is a very dominating instrument. I guess this goes back to when I was 7 years old and I was able to play and get into myself without any other instrument. The jazz bands in New Orleans — you see these guys marching down the street, there’s no piano. …

“The kind of music without a piano is more gritty, more real, hard jazz. It allows me to feel more free in my improvisations. The piano is very leading. You can lead a band here, you can lead to this chord, this mood. Everything is fed by a piano. I find that very restricting.”

Instead, he uses a guitar. “[It] gives me a harmonic foundation, and yet is not as dominant.”

He’s currently working on a project to be called Road Shows, a compilation of live songs and entire concerts from the 1970s through 2000 — “What could be considered bootlegs in many cases” — that he hopes will be out this fall.

He calls himself “one of these overly critical artists” who doesn’t like listening to his old concerts. When he does, he says, “I’ve found some things that are surprising to me. Just my playing — I played some things which I’d forgot I’d played.”

Rollins says he’s happy to be returning to Newport: “It’s a nice festival, and I’m looking forward to coming there again. One remembers the tradition of the Newport jazz festival, and it adds a little extra incentive.” And as long as his health holds out, he’s going to play, tour and record as much as he can. (He’s already put out three records this decade.)

“I’m still searching for something. I came into music sort of late in a professional sense, and by the time I came out of high school, I loved music but I had no idea that I was competent enough to be a professional musician. I got that assurance from people like Thelonious Monk and Miles Davis, so I thought, ‘OK, I must be OK to be here.’ But I still consider myself a work in progress.

“I still practice every day and am still searching for my lost chord. And I still hear some music which I don’t get to enough when I play. Every now and then we have a successful concert and I think we’re getting there. But I haven’t gotten my music together yet to the point where I can really feel satisfied with it. I may never, but I want to get a little closer to what I’m hearing.”

He recalls the story of how Charlie Parker was once asked what he was going to play that night, and he said, “I’m going to play what happened to me today.”

“And this is jazz,” Rollins says. “To comment on what is happening in the world, on social conditions and all of these things. So what

I’m trying to do is changing because things change. …

“I’m still learning every day.”

Sonny Rollins plays on the Fort Stage on Sunday.

rmassimo@projo.com