A man sits at the piano and - across seven decades - the magic happens: Master imparts wisdom to student.

Jazz giant Billy Taylor, 87, is giving pointers to budding pianist Donté Ford, 17. Taylor spreads his famous left hand over a dozen keys and ripples off a chord.

"That looks like it hurts," says Steven Fox, 17, also a pianist.

Taylor, bandmate of Bird, Duke, Dizzy, and Miles, surprises them by saying, "Sure it does. But keep on doing it. I don't have a big hand. I just had to work at it."

Taylor is visiting the Girard Academic Music Program, a magnet secondary school at 22d and Ritner Streets, as part of the Mann Center for the Performing Arts' Education and Community Engagement Program. Students in grades nine to 12 get to learn from real pros close-up. Taylor, a natural teacher and the man who first called jazz "America's classical music," has come to teach, show, and, most of all, listen.

As the Girard program jazz septet performs his tunes "Gracias Chucho" and "Transformation," he nods to the beat, beams at the solos. Drummer Devon Waring, 17, makes him smile with an assured stroll, as do trumpeter Jawan Bennett and reed man Andrew Lawson, both 17.

In his comments, Taylor starts with praise: "Everything was very well played." He couches suggestions in encouragement: "What you want to work on now are the things you can do to say who you are, what you want to say." He counsels constant practice, openness to all kinds of music ("Jazz is a way of playing, but there is no one style"), having "a conversation with the band."

In a question-and-answer session, Taylor recounts lessons from sax-god Coleman Hawkins and piano original Thelonious Monk.

He shows almost disconcerting humility about going back to school to get his doctorate in music education, which he earned at 53, from the University of Virginia in 1975. "It was very difficult to go back," he says. Somehow, though, the way he says that makes the hard seem - doable. That's a teacher talking.

Taylor's been doing that since at least 1964, when he founded Jazzmobile Inc., a prominent jazz education nonprofit in New York. Robin Bell-Stevens, president and chief executive officer of Jazzmobile, says, "Billy was the first to create a curriculum of jazz education for nonmusicians."

Taylor goes to play a little, explaining that "I play everything I used to play, only some of it's a little slower now." He slips into a slowed-down, bluesy "Take the 'A' Train" with a deliciously wandering left hand.

The Girard program choir performs two numbers, then joins with the combo for a rousing version of "I Wish I Knew How It Would Feel to Be Free," Taylor's best-known composition. By the time music technology and percussion instructor Vincent Rutland spreads his arms for the big finale, everyone's applauding.

Amid the happy milling onstage afterward, Rutland says, "I thought it went very well. It's a privilege to try to play up to his standard."

Do young people today listen to jazz? Those in the Girard program do. Percussionist Shakoor Sanders, 16, says, "My dad used to play Miles Davis all the time, the Kind of Blue album, which was a big inspiration." Flutist Tiana Landi and saxophonist Bilha Pierre, both 17, started in classical. Teachers inspired sax player Christine Witmer, 17, and Lawson. The latter says, "My teacher gave me John Coltrane, My Favorite Things, and the impact was ridiculous. It really involved me. A Love Supreme was next."

But what do you say to friends who listen only to hip-hop? Drummer Waring says, "I tell my friends that in jazz, you can be free in ways you can't in other kinds of music."

The magic happens when Taylor starts speaking to Bennett and Lawson about the art of the solo. "Listen for the direction and the structure of the melody . . . build on that melody, build something on top of that structure . . .."

And the students, all big eyes and tuned ears, gather round and listen. "Let me show you," he says. He moves to the piano, and it's as though a soft, human wave of young musicians carries him there.

That's where he sits, spreads his hand, and plays.

"You make it look so easy," says pianist Ford.

"It's not," says the master.