About the only stable element at the Dance Theater of Harlem is its commitment to developing black classical dancers. Notions about what they should dance change from season to season. Last year's theme in repertory was standard European classics. This year, the word is American dramatic ballet.
By the time Dance Theater's run at the New York City Center is over, on Feb. 14, the company will have presented as many as four new productions of story ballets. Two of them have already been premiered during the first leg of the season - Valerie Bettis's ''A Streetcar Named Desire,'' based on the Tennessee Williams play, and John Taras's new version of ''Firebird.''
Debates about the wisdom of transferring theater into dance will continue as long as choreographers keep doing it. But one thing for sure about the dancing ''Streetcar'' is that it shows the dancers to be powerful actors.
One reason Williams's play is wonderful is that, no matter how beastly the characters behave toward one another, they still seem sympathetic. Nuance of character, and the audience's complex response to character, are usually the first things to go in these transplant operations. But with the sensitive, well-calibrated performances of Lowell Smith as Stanley Kowalski, Virginia Johnson as Blanche, and Elena Carter as Stella, the story brims not only with violence and heartbreak but also with humor and tenderness.
Such is the conviction of the dancers - those in cameo roles as well as the leads - that Bettis's contributions as choreographer go almost unnoticed. In some sense this is justified, because the dancing per se is the weakest aspect. Blanche's long dance monologues, where she reaches deeper and deeper into her tragic past, hang on a thread of dance interest. What's compelling about them and other such moments is the sure and convincing way they establish atmosphere and tie in with later passages, ultimately meshing into a theatrical whole.
Despite the sags, Bettis's ''Streetcar'' ends up with the audience in its grip. With its evocative juxtapositions between the seamy and the fragile, between debilitating lies and necessary illusions, Bettis's ''play'' is as seductive as the real thing.