LEAN AS a whip, he twists sinuously with the music that is coming from his flute. His eyes are closed. People slow down as they walk past. Every now and then someone darts up and puts money in the flute case on the sidewalk in front of Raleigh's.

It is a spiritual, "How Great Thou Art," done with professional skill and an emotional power that turns heads clear across Connecticut Avenue. An old woman stops and points with concern at the coins.

"Watch out," she says. "You keep an eye on that."

Ebrahim Shakoor nods and smiles at her."It's all right," he says.

This is his place from noon to 2. "I start at 7:30 at 18th and K, and then in the evening rush I'm at Farragut North station. I work about a nine-hour day."

And on a Friday night he might play on the 19th Street strip, and on weekends maybe at the Market Street Gallery on the Hill. He has been giving music to Washington for eight years now: jazz, spirituals, ethnic, classic. Sometimes a friend will join him with a saxophone.

"My father died in '62 and I was left the man of the house, and I began running in the street, up on 14th Street. Hustling. A lot of negative influence. I was in and out of Lorton, but when I got out the last time in '72 I thought: No more."

For awhile he went to Washington Tech, now UDC. He thought he should be a sociologist because of what he knew about being an ex-con and a kid in the city. Then he was a staff aide with the Boy Scouts.

When he was little he had fooled around with a toy flute, and he still liked to play it, and one day, Sept. 15, 1972, to be precise, he went to Sam's Pawnbrokers at 14th and P and bought a real flute.

"I learned on the street, man. I learned to read music. I taught myself."

Two years ago, turned down for a grant by the National Endowment for the Arts, he went to Europe with the money he makes from playing--it may average $40 to $50 on a good day--and was promptly discovered. He sat in with Dizzy Gillespie at a jazz festival in The Hague .

"Dizzy Gillespie! He told me I could play anywhere . . ."

Then a German group, El Duo Flamenco, picked him up, and he did the title tune for their album, "Morera." They brought him back to Europe a second time and toured with him as their guest artist.

"I played in opera houses where Mozart played," he says softly.

A few months ago he returned from a third trip to Europe, and things are slowly looking up for him in his native city. He sits in with various groups that come through town. He was first flutist with Don Cherry's DC Jazz Workshop orchestra, playing at the Pension Building and d.c. space.

But the street music is his living. Sometimes the police fine him for being off his allotted beat, and this baffles him. "It's not like I'm a car or something. You know I'm gonna be here. You know someone's always gonna be here giving you positive energy."

They do know it, too, most of them. "Babies really react to the love being given, man," he says. "Old people who can hardly walk. I don't worry about dates or success or promotion as long as I can be in touch with people."

He says he wishes he could reach those others, the ones with the wooden faces, walking numbly through the bright days.