After his death in 1974, the Calvert Street Bridge was renamed for Duke Ellington, a dubious honor, since the bridge has long been known as a suicide site. Then Western High School became the Duke Ellington School of the Arts, a considerably more appropriate award for a man considered by many to be one of America's greatest composers. But Washington hasn't exactly heaped honors on native son Edward Kennedy Ellington.

The jazz world was shocked when it learned a year and half ago that band leader Mercer Ellington, the Duke's son, had donated some 50 boxes of unreleased studio tapes, interviews and memorabilia to Danish Radio. Ellington defends the donation on the grounds that no one came forward "who would guarantee us that they wouldn't be stacked in some dry, safe room to collect dust rather than be out where people would know something about Pops one day.

"I was told that the folks at Danish Radio would be glad to preserve them, to transfer them and use them," recounts Ellington, who purchased a home in Copenhagen three years ago. "They have a broadcast every Sunday of Duke Ellington taken from these tapes. So there is a mindfulness that is kept of him, and this is one of the things that I asked."

"I would have made an offer," assures Maurice Eldridge, principal of the Duke Ellington School, of those precious tapes now in the custody of Danish Radio. Eldridge is confident, though, that the events taking place Friday at the school's inauguration of its new theater will "make him Mercer Ellington take us seriously."

The day's events will include an early-evening reception at the British Embassy hosted by Ambassador Oliver Wright and Lady Marjory Wright; an afternoon jazz workshop by Reuben Brown and two of the school's prize graduates, trumpeter Wallace Roney and his tenor saxophonist brother Antoine; a reading in the drama department by novelist Nikki Giovanni; and appearances by actors Carl Anderson and Danny Glover.

In the evening, dancer Mercedes Ellington, Mercer's daughter, will perform a work dedicated to her grandfather, and Mercer Ellington will lead the Duke Ellington Orchestra. Emcees will be Charlie Rose of CBS' "Nightwatch" and Channel 9's news team of Maury Povich and James Adams. The "Ellington Salutes Ellington Gala" will launch the school's annual fund-raising campaign.

"I think it's a significant step in the life of the school," says Eldridge of the new theater. "And I'm excited about having both Mercer Ellington and Mercedes Ellington here. We expect that the theater will be a major part of the training that the school offers its students and, at the same time, that it will be an important performance space for other people in the city."

Eldridge hopes the new theater will be used both for school productions and for "shows that come in from outside with apprentice oppor tunities for our students to work backstage." Eldridge expects a resident repertory theater company to be established and says a study has been commissioned to explore "how to market and manage the facility as both a laboratory and an entrepreneurial enterprise." The theater will be used by all of the school's departments, which include instrumental music and voice, dance, drama, painting, sculpture and photography. Eldridge says he hopes cinema, television and creative writing eventually will be added to the curricula.

He concedes that the music program at the Ellington School "has been frankly classical in its orientation from the beginning," but points to the recent incorporation of jazz in the school's offerings. Washington-based jazz players Noble Jolly and Chris Royal are teaching there, and a grant-supported program is bringing in jazz masters to give workshops.

"I'm working to strengthen what we do in jazz ," he says. "I think it's important that we develop a sound program so that our kids really know what the heritage is."

Mercer Ellington insists that his countrymen "have a lot to prove" in recognizing the art form to which he and his father have devoted their lives.