The late-summer air outside Germantown's Club La Rose was hot and still. The streets were mostly empty, the stores closed.

Then the soulful sound of a saxophone pierced the stagnant swelter like a crisp breeze.

For 35 years and counting, Tony Williams has spent Monday nights bringing old-school jazz to Philadelphia. There may have been different backup players and various venues over the decades, but the passion that Williams, 77, brings to his music has remained constant.

Inside the cool, dark club, the men wore ties, the ladies, hats. They watched Williams, in a tan suit perched on a stool in front of a grand piano, playing each song as if he'd never played it before.

"Nobody I met all through the years can blow the sax like he can," said Al Brealand, 94, a lifelong jazz fan. "He's one of the best."

Williams is more than a jazz musician. He's also a dedicated teacher and promoter of what he calls "the only American art form." Determined to teach the old ways to a new generation, he cofounded the Mount Airy Cultural Center, a 30-year-old organization that offers free music lessons to dedicated young musicians.

"If people like Tony weren't around, I don't know where jazz would be," said Bob Perkins, a respected jazz radio personality. "He's been a mentor to many people in his lifetime."

Williams and some of his students past and present will perform at the 18th annual Tony Williams Scholarship Jazz Festival, which will run from Friday through Sept. 1 at the Holiday Inn in Fort Washington. Special guests will include Grammy-winner Cissy Houston as well as comedian Bill Cosby, a jazz drummer and longtime Williams friend. Festival proceeds will fund scholarships for MACC students.

Kim Tucker, a music coordinator working with this year's festival whose mother, Sue Ford, was a longtime supporter of local jazz musicians, summed up Williams this way: "Tony cares."

Williams prefers what Perkins calls "straight-ahead" jazz, but notes that jazz "is not basic. It can never be basic." His playing style has been compared to John Coltrane's and Stanley Turrentine's.

But Williams said every jazz musician is different because of the improvisation.

"You have a chance to express it how you want to. Where you come from, how you jumped rope, it all gets in there," Williams said. "This music gives you freedom to express yourself. Everybody that breathes can have something to say."

Williams learned this from his cousin, a saxophonist named Thaddeus Thurman. As a boy in Tennessee, Williams accompanied his cousin to gigs, often sitting on the stage. "He would always tell me, 'I want you to listen and see what you get out of it.' I learned a whole lot by just listening," he said.

Williams started saxophone lessons when he was 10 years old - he had to wait until his fingers were long enough to get the fingerings right - and performed with his cousin a year later. The older musicians encouraged him.

Williams moved with his family to Willow Grove when he was in junior high school. After graduating from Abington High School, he eventually settled at Central State University in Ohio. There, he said, "my music began to flourish." He graduated with a degree in physical education and then joined the Army, playing with the 75th Army Band stationed at Fort Belvoir, Va.

His military service complete, Williams returned to Philadelphia and began teaching. Soon he was married with a son, and he needed extra money.

So he pulled out his sax and began playing cabaret parties with musicians like Mickey Collins. He joined the house band at Rathskeller, a now-defunct Broad Street club, that "was the beginning of my notoriety."

His professional clout kept building. He worked with Wild Bill Davis, Dakota Staton, Donald Byrd, Nat Adderley, Gerald Price Jr. For about a year, he played in the house band for You Bet Your Life, hosted by old friend Cosby and filmed at WHYY. The two had met when Cosby was at Temple playing drums in a jazz band.

"Bill was a good drummer but he was always clowning. So they fired him," Williams said with a laugh. "He is a lot of fun to work with."

Over the years, Williams had numerous offers to tour and make music his main vocation. Instead, he stayed local. During a 30-year career in city schools, he taught health and physical education, coached track, basketball and soccer, and served as a vice principal.

"I loved teaching," Williams said. Plus, the alleged glamour of a musician's life was one thing, "but I had a family, and I felt they needed structure."

Perkins said visiting musicians would play with Williams and immediately want him to join them on the road.

"People would try to steal him, but he has roots here," Perkins said. "Like Bootsie Barnes. They could have been international in a heartbeat, but for 100 reasons they stayed local."

Williams does not regret that decision. He did some overseas touring but also built a stable home with Gloria, his wife of 53 years, and their three children.

"Philadelphia has been wonderful to me. I used to hear people say, 'You can't make it unless you go away from your home.' Well, I broke that tradition," he said. "I've had a chance to do my music and the people have been gloriously nice and supportive. Life has been really good. If I were to pass the picket line right now, I would not feel sorry for myself."

The Mount Airy Cultural Center started because Williams and some fellow teachers - including Tommy Grice, who still teaches with the program - were not happy with what they heard their students listening to in the 1970s. "We were sick and tired of all those boom boxes and this loud music. We wanted to keep jazz alive," Williams said. "We said, 'Look, if we want to hear some good music, we have to be sure it exists.' "

So like his cousin before him, Williams began teaching the next generation.

Williams and the other instructors offered free classes after school and on weekends, at school and at their homes. Stenton Diner owner Hunter Bugg opened his establishment's doors for Thursday night rehearsals.

Musical talent didn't matter as much as commitment did. Although most in the first group of 25 students were already playing instruments and could read music, Williams was interested in "kids who might be banging on the table wanting to play drums or singing or just excited by the music," he said.

Markanthony Henry, one of the first students to go through the program, remembers being 10 and hearing Williams play for the first time.

"I had never heard anything like that before. When you hear a style that's so expressive, it just fascinates you," said Henry, now the director of the music festival. "I didn't understand it at first."

The program grew quickly and, over the years, hundreds have been taught, many of them now professional musicians.

"I get a great satisfaction out of a kid starting out, with nothing, and then he picks up a trombone, he picks up a sax, and he plays a song and surprises me," Williams said. "Young people pass on their energy. I don't mess with old folks too much."

Now MACC is officially a nonprofit and holds classes - currently at Grover Washington Jr. Middle School at B Street and Olney Avenue - Saturdays during the school year from 9 a.m. to 2 p.m. The first part of the day is devoted to individual instruction, the second to theory and group play.

The program has about 45 students, including sisters Chandra and Chelsea Holloway, 19, who play saxophone and clarinet, respectively. Both have worked with "Mr. Tony."

"He's amazing. When playing with him, even just trading measures, I go to another level," Chandra said.

The program is demanding, especially for teenagers who would rather sleep in.

"Sometimes, I thought, 'I don't want to get up.' But I'd get up," Chelsea said. "The praise and applause you got when you got there was worth it."

MACC requires commitment from parents, too - no dropping off children and driving away. Parents take part in everything from weekly lessons to special performances. (Williams calls the relationship a "tripod," with the teachers and the parents supporting the student.) The twins' mother, Bernadette Holloway, has devoted nearly as much time to MACC as her daughters have.

"Tony has energy," she said. "You expect him to be toddling, but not Tony. He's always got something going on."

The current lineup of the Tony Williams Quartet has been together for about five years. The musicians are so in tune with each other that they don't rehearse often or prepare set lists.

"We don't know what we're going to play. We could play anything," Williams said. "Someone could walk in you haven't seen in 15 years, but you remember them and you play a song you know they like."

Music appreciators such as Perkins, the radio personality, marvel at that ability.

"When a musician like Tony can give you a particular song, be it a standard or a pop song or a jazz tune, and play it for you 100 times and each time it's different, without reading a piece of music - that's magnificent," he said.

Williams describes the Monday sessions as "therapeutic." He watches his audience carefully.

"Sometimes they come out, and they don't know what's going on. They're by themselves. They look uptight. When I see that, I try to make an expression at them so they feel at home," Williams said. "The camaraderie is great and the music seems to be good, according to the applause."

More than good, Kim Tucker said. Truly healing. "Tony's playing is very soulful," she said. "If you have a problem, you don't think about it. If you were feeling sad, you don't any longer. It's a gift."

Williams and his band ended that recent Monday night with a version of "When the Saints (Go Marching In)," which was so lively and engaging that it pulled nonagenarian Brealand from his seat. He shuffled and snapped alone until a woman grabbed his hands and made him her partner.

The waitstaff danced past them, clearing glasses. At a stageside table, an elderly man who had been silent the entire evening laughed out loud as he watched his wife sing and wave one arm in the air.

"This is real music, and we enjoy every minute of it," said Bob Wells, 65. "I'll make it a point to be here every Monday night until the day I die."