Donald Harrison Jr. is tired. He was tired yesterday, and he will probably be tired tomorrow. For that, he blames Miles Davis.

Harrison is the only world-class modern jazz saxophonist and composer who is also a Big Chief in the Mardi Gras Indian tradition. In the 1980s, as a young man still honing his craft, he played some shows with Davis and hung out at the legendary trumpeter’s Manhattan apartment.

“I watched this man working on about six projects,” Harrison recalled recently. “He was painting, he was writing a song, he was watching and commenting on a movie. He’d take a few minutes to look at the newspaper. He had a designer coming by with clothes. He was talking to me at the same time — just a whirlwind of activity.”

At 55, Harrison is the calm center of his own whirlwind of activity, especially throughout the New Orleans Jazz and Heritage Festival presented by Shell.

Among other commitments, on Monday, April 25, he’ll be inducted into the Tipitina’s Wall of Fame during the club’s annual Instruments A Comin’ benefit concert. He’ll also perform alongside his students from the Tipitina’s Internship Program.

On Tuesday, April 26, Harrison headlines at the Orpheum Theater, one of the highest-profile hometown shows of his career. He and his band will showcase everything from his contemporary, sometimes challenging, “nouveau swing” jazz to Mardi Gras Indian music to soulful R&B.

“We play it in a way that is logical and feels good for the audience,” he said. “We take them on a journey.

“My perspective is that all music should be about the mind, body and soul. If you’re an intellectual, you can intellectualize it, because it always has those elements of stretching for the highest level that you can be on. And it should feel good. I like toe-tapping music better. No matter how far we stretch it, you still can feel a groove to it -- basically, I may be teaching jazz people to have some fun.

“And it should hit you some kind of way in your heart. All those ideals are present, I hope, when I play.”

After the festival, it’s back to his usual, equally busy routine.

He’s on the road most weekends. He’s working to finish his first orchestral piece, “Congo Square,” which he hired the Moscow Symphony Orchestra to record. He’s working on a commission that will premiere in June in New York with the Hartford Chamber Orchestra.

And, as always, he’s teaching the next generation.

Back when he was around Miles Davis, Harrison thought, “ ‘Boy, he’s achieving a lot.’ I realized how lazy I was. I started doing a lot of things like I saw Miles doing at his apartment that day. I realized that you could achieve more if you worked a little harder.”

He laughed. “I think that may be the thing that messed me up.”

An Indian at age 2

Harrison literally grew up as a Mardi Gras Indian. His father, Donald Harrison Sr., was a legendary Big Chief who led the Creole Wild West and White Eagles tribes before founding the Guardians of the Flame in the late 1980s. He died in 1998.

Young Donald first “masked Indian” at age 2. He was also exposed to the bebop records his father played around the house. Those two influences “give me another perspective,” Harrison said. “Knowing where the roots of some American music came from, to the outer limits of where American music has gone, I feel like I have the full perspective. From where it started to where it’s going, and all the points in between.”

At 16, he discovered fabled saxophonist Charlie Parker; bebop in general, and Parker in particular, became his obsession. He spent years “trying to understand how that music is put together. Charlie Parker was the key to it for me.”

He didn’t mask Indian while attending Francis T. Nicholls High School and the New Orleans Center for Creative Arts. Instead, he studied jazz and played with brass and R&B bands.

‘You’ve been born again’

After graduation, he spent a year studying under Alvin Batiste at Southern University in Baton Rouge, and with avant-garde saxophonist Edward Kidd Jordan.

He moved on to the Berklee College of Music in Boston. At a jam session in New York, he met Roy Haynes, the legendary jazz drummer and alumnus of Parker’s quintet. After hearing Harrison play, Haynes called him over and said, “You’ve been born again, brother.”

He meant that Parker’s spirit had seeped into Harrison. Much to Harrison’s shock and amazement, Haynes hired him for his band.

At age 20, Harrison landed a gig with jazz-soul organist Jack McDuff. Soon afterward, he joined drummer Art Blakey’s Jazz Messengers and withdrew from Berklee.

He never went back: “I want to do it at some point, but it doesn’t seem like it’s going to happen.”

A jazz proving ground

Blakey’s band was a proving ground for up-and-coming musicians. Its ranks included New Orleans trumpeter Terence Blanchard. Blanchard and Harrison formed their own quintet, which released five albums in the 1980s.

By the end of the decade, they had gone their separate ways. By then, Harrison was firmly established. His subsequent albums have ranged across the spectrum of contemporary jazz. At performances, he usually wears a suit and tie, but he is often joined onstage by Mardi Gras Indians in full regalia.

And he is still learning from the masters. For years, he’s been in a trio with former Miles Davis bassist Ron Carter and drummer Billy Cobham.

“Those guys do that band so they can impart their knowledge to me, so I can pass it on the right way,” he said. “Music is infinite. There are always new vistas and new horizons. I guess I’m an explorer. A tired explorer. But relentless.”

His explorations finally led him back to Mardi Gras Indian culture in the 1990s, when he founded the Congo Nation.

“At first, I didn’t want to be a chief, but I couldn’t fight it anymore,” he said. “Because it’s so much responsibility, I didn’t know how I would be able to play music and be a chief too. It’s a full-time job, really. I didn’t know if I could do two full-time jobs. But I figured out a way.”

Harrison does not refer to the Congo Square Nation as a Mardi Gras Indian tribe. Instead, it is the Congo Square Nation Afro-New Orleans Cultural Group.

“Which is a long title, but I think it accurately describes what we’re doing. I realized that the music that we play is not Native American. It’s African, with call-and-response chants and African-style percussion.”

The design of his elaborate, beaded and feathered “suits” does not adhere to either Uptown or downtown Indian tradition. “It has elements of the Uptown style, but now I’m incorporating elements from Africa, as well as elements from America. I’m not an African, but I know the roots of where I come from. And my heart feels like Africa.”

This year, his mother and sister pitched in to finish sewing and beading his suit. Time, as always, was in short supply.

“I had a lot of help this year because I was so far behind. But we made it.”

Passing the craft along

On a recent Monday night, Harrison sat at an electric keyboard inside a rehearsal room in the Fountainbleau storage and music complex on Tulane Avenue.

A dozen high school students from the Tipitina’s Internship Program sat in close quarters under a low ceiling and fluorescent lights, the sort of unglamorous space where dues are paid and craft is learned.

Harrison has mentored successive classes of interns most Monday nights for years, despite the demands of his own schedule. As elders likes Haynes, McDuff, Davis and Blakey once did for him, he wants to both pass on the music and inspire students to create their own.

“One objective is to give them an easier way in the music business — I had such a hard way. But also help them have a broad-based source of knowledge, and let them choose what they want to do with their careers. Because it’s not my choice. It’s their choice.

“If you know something, you can choose not to do it. But if you don’t know it, you can’t choose to do it.”

Roland von Kurnatowski, the real estate developer who owns Tipitina’s and led the renovation of the Orpheum Theater, is especially impressed with how Harrison deals with students.

“Donald has a way of working with young people that is at the same time respectful and authoritative — very effective,” Von Kurnatowski said. “He is a class act, and his passion for working with the interns is infectious. He has the poise and self confidence that is exhibited by someone who is truly comfortable in their own skin.”

At the recent session, Harrison called out the students one by one to see if they’d done their homework, which involved intimate knowledge of musical scales. He challenged one of several bassists in the room: “Do you know it?”

The boy mumbled sheepishly about needing to go over it.

Harrison scolded him: “You can’t lose this stuff.”

Another bassist, 18-year-old Dermell Lewis, took a stab at the Jaco Pastorius song “Teen Town.” Lewis finger-picked his five-string bass, impressing Harrison with his speed and precision.

“I’m proud of you,” Harrison said, before addressing the whole class. “I can only go as fast as you can go. You make the choices of how far you go by the amount of effort you put into it.

“You have to be relentless, and it will pay off.”

He was speaking to his students, but he might as well have been speaking about himself.