A young man with a bubbly Jamaican accent was going door to door in the plush Wesley Heights neighborhood, reciting a Horatio Alger spiel about himself which ended in an appeal for subscriptions to several obscure magazines.

He found Peggy Cooper at home. She was being interviewed about her new position at the top of the District of Columbia arts world.

"Boy, oh boy," he sang out. "I didn't expect to find someone like you." Cooper appeared as young as the salesman himself. Even more surprising, in this ritzy Northwest enclave, was the fact that she, too, was black.

He asked her what she did for a living. She said she was a lawyer and that she was active in the arts. How did she get where she was, he wanted to know.

"Education," she replied. "And anger."

Finally the conversation turned to magazines. Cooper offered to write a short testament to the salesman's skills and to contact him later if he were willing. But she firmly maintained that she would not buy any magazines today, thank you.

Yesterday the city council, acting as a committee of the whole, approved Mayor Marion Barry's appointment of Peggy Cooper as the new chairman of the D.C. Commission on the Arts and Humanities.

Her predecessors in the unpaid job generally played a passive role, allowing the commission's executive director to set the city arts policies. Cooper does not plan to follow suit.

She wants to abolish the commission. If Cooper has her way, within 18 months the commission will be subsumed, along with other city arts entities, in a new office of Cultural Affairs. Barry supports this course, she says.

Her most startling short-term goal is to disband the current panels of volunteers that recommend approval or disapproval of grant applications. She plans to "start from scratch" with the panels, hoping to assemble new ones by the summer in order to evaluate the grant applications for fiscal year 1980.

She wants to explore alternatives to the current panel system, and to hold hearings on the conflict-of-interest issue that has afflicted some of the panels. Cooper believes that anyone receiving money from a grant applicant should not serve on the commission or on the panel that rules on the applicant's bid for funds - a position significantly less permissive than the commision's current conflict-of-interest guidelines.

Unpaid board members of organizations that apply for grants could still serve - as long as they leave the room during consideration of the applications with which they are affiliated.

Cooper, 32, is herself an unpaid board member of the Ellington School of the Arts and Workshops for Careers in the Arts, two organizations that she founded. She won't resign from the boards, but if the organizations were to apply for commission grants, "I should be 15 miles away from the room during consideration of their applications," she says.

The commission has lacked a coherent philosophy, says cooper, and she intends "to deal with it. You have to have some kind of philosophy and the guts to stick to it in order to create guidelines," she says.

The commission also has been criticized as mismanaged. "I really plan to see the place is straightened out," says Cooper, "that a tight ship is run, that growth takes place."

Currently the commission's administrative costs make up nearly a third of its budget; Cooper wants to reduce that figure to a maximum of "20 to 25 percent."

However, she also wants "to build the most skilled and competent staff of any arts agency in the country." She warns that "if I find out the commission is in a horrible mess, there may be a while when we have to keep the administrative proportion up.

"Any staff should be measured by the amount of substantive work it creates for itself," she adds. "There are gobs of things to do. I could take a staff of 50, have 'em work like hell and have things happening."

Cooper stresses that the D.C. Arts Commission has more work to do than an average state arts agency, for it is also a municipal arts department.

Sometimes the D.C. Commission might even play a federal role, she says, because of its location in the nation's capital. Congress has been asked to maintain the buildings of Arena Stage, the Corcoran Gallery and the Folger Library - partially because the District lacks a state arts agency, according to Folger director O.B. Hardison. Cooper says city arts officials should be consulted on any such decision.

She believes the groups deserve the money, but she would like "to see the pot increased" to include more minority-oriented institutions such as the Ellington School and the new arts center planned for the downtown Lansburgh's building.

One of Cooper's central concerns is "to bridge the great divides" that separate the various arts constituencies in town: federal/local, black/white, established/emerging. "The National Symphony shouldn't see everything else as a threat, and the Miya Gallery (a small minority-oriented arts center) shouldn't see the National Symphony as the Loch Ness monster. They can help each other. They don't need to destroy or to homogenize.

"The city is in a better position to get more money if there's a united front," says Cooper.

Peggy Cooper has made her reputation by crossing cultural divides and raising money.

Her middle-class parents in Mobile sent her to a boarding school in Indiana that was almost all white. After graduating, she returned home for a summer of civil rights activity, then arrived in Washington as a GWU freshman in 1964.

While still an undergraduate, she began the arts training program for teen-agers that eventually evolved into Workshops for Careers in the Arts and the Ellington School. According to her resume, she raised more than $6 million for this project in eight years (though she says she "hates" fund-raising: "It's nothing but begging"). She became adept at mingling with philanthropists.

"My father often said to me that he wanted me to be as comfortable sitting in a melon patch as I would be in an audience with the Queen of England," says Cooper, "as comfortable reading Aquinas as I would be reading W.E.B. Du Bois. You are supposed to be wherever you are, he said. I never felt any fear about where I belonged."

For five years Cooper has lived with Conrad Cafritz, a scion of one of Washington's wealthiest families. They are, "for all practical purposes," married, she says.

Cooper has already served as a D.C. arts commissioner. She was appointed when was 22, in 1969, and served until 1975. Recently the commission has been criticized as little more than a rubber stamp for the decisions of the panels and staff, but Cooper says the commission was not that way during her earlier term.

"Of course there were far fewer arts organizations in the city," she adds, "and it was easier for the commissioners to be aware of what was going on."

Cooper claims one artistic skill: "I can produce television shows. The chance to do it came late, but I learned very fast."

She worked fr Post-Newsweek Stations, Inc. as an assistant to the president and a documentary producer from 1974 to 1977. She left Post-Newsweek to work on a proposed public television series with Harry Belafonte and Carl Holman of the National Urban Coalition. But after an expenditure of $53,000 and the writing of eight treatments, the project failed to sell.

Cooper projects a disarmingly youthful air, sprinkling, "okay" through her conversations and smiling easily. But she can get riled fast on the subject of public television.

She refers to "years of incredible racism" at the Corporation for Public Broadcasting, and she is not impressed by WETA, Washington's public TV station. Though WETA is licensed to Washington, its studios are in Arlington, and Cooper does not feel its programs are "responsive to its constituency. We should demand total respect from WETA and make sure that its first priority is to serve Washington," she says.

When Cooper speaks like this she is not just speaking as the chairman of the D.C. Commission. She is clearly Mayor Barry's major arts adviser. She was the member of his transition team who was delegated to the group that wrote a report for the mayor which was highly critical of the D.C. Commission. If the Office of Cultural Affairs, which was recommended in that report, is ever born, Cooper is a likely candidate to lead it.

As for political ambitions, she denies them. She once assumed she would run for office, she says, but now "my personal life is something I cherish too much."

The way Cooper looks at it, giving to the arts is "just beginning" among the blacks of this black-majority city. Until now, blacks have been saving their money for school, she says, but "among my age peers, they contribute heavily. And they're pretty sophisticated about what to support.

"Washington is a very affluent black community," she says. "The largest proportion, of course, is first-generation affluent."

She acknowledges, however, that "there aren't enough of us yet. The majority of power in this city is black, and the majority of money is white. We've got to bring the two together.

"At some point in this society," says Cooper, "everything has to converge." CAPTION: Picture, Peggy Cooper, by Larry Morris-The Washington Post