The high point in the Dance Theatre of Harlem's repertory sampler at the Kennedy Center Opera House last night was a relatively new company acquisition -- Glen Tetley's "Voluntaries," created in 1973 to Poulenc's Concerto for Organ and Orchestra, and staged for DTH by the choreographer last year.

Tetley's "fusion" choreography splices modern dance movements -- specifically those from the Martha Graham lexicon -- into the grammar of classical ballet. Thus, to the extended body line of ballet, with its "pointwork," are appended the muscular contractions, folds, dives and falls of the modern idiom. It makes for an athletically spectacular kind of dancing, accentuated by daring forms of lifts and partnered spins, as well as a physically demanding one. The DTH cast for "Voluntaries" appeared to revel in the challenges, and the work, in turn, seemed flattering to the dancers.

Tetley choreographed "Voluntaries" for the Stuttgart Ballet, as a memorial to its artistic director, John Cranko, shortly after his death -- Tetley himself was Cranko's successor as head of the troupe for a time. Perhaps by virtue of its inspiration, it has always seemed one of Tetley's most successful ballets -- more satisfying as a compositional whole than most of his works, more lucid, more convincing in its imagery and flow. There's an elegiac gravity to it too, that matches the sourly plaintive strength of Poulenc's score.

All this was underlined last night in a performance led by Yvonne Hall and Augustus van Heerden as the lead couple, Stephanie Dabney, Joseph Cipolla and Donald Williams as the subsidiary trio, and six supporting couples. Hall and van Heerden had a magisterial solemnity that lent Tetley's abstract, gymnastic writhings the undercurrent of seriousness they need, and Dabney's sharp attack spurred the trio into effective counterpoint.

The rest of the program consisted of two company "standards" -- John Taras' version of Stravinsky's "The Firebird," with its lush tropical decor by Geoffrey Holder, and Balanchine's "Serenade." The chief attraction of "Firebird" has always been Dabney's lithe, proud, iridescent performance of the title role, the magical forest creature who ensures the triumph of true love over adversity. Though the choreography otherwise consists mostly of pageantry, processionals, and -- in the case of the Creatures of Evil -- goblin calisthenics, Dabney once again cast her spell, with admirable help from Donald Williams as the Young Man, Lorraine Graves as the Princess of Unreal Beauty, and Darrell Davis as the Prince of Evil.

"Serenade," the evening's one authentic choreographic masterpiece, seemed almost lifeless in last night's DTH account of it. The powerful descending melody at the start of Tchaikovsky's music, which should be suffused with rhapsodic melancholy, sounded chloroformed instead, in the lethargic tempo conductor Boyd Staplin chose. The tempo picked up after that, but not the soggy spirit of the performance. The dancing was respectable, but it was just a matter of going through the motions. Perhaps the piece needs to be retired for a while? Something needs to be done to restore the company's sense of spontaneity in relation to it -- dancing Balanchine ballets with a special spark has been a DTH tradition of long standing.