It was a distinct pleasure -- if not an entirely unalloyed one -- to welcome the Alvin Ailey American Dance Theater back to the Kennedy Center Opera House last night. The troupe, long one of the nation's outstanding dance ensembles, is here for a week, and its opening program last night marked not only the start of the season's new Dance America series, but also the company's first visit to Washington in three years. Before that, Ailey had been one of the hardy perennials among our dance guests, and a great popular favorite at that. It's good to have them back.

The first-night performance, though not without highlights of multiple sorts, was a mixed bag. On the down side, for instance, was a surprising lack of kinetic voltage through much of the dancing -- surprising because the first thing one thinks of in connection with Ailey is the visceral charge that has been the troupe's most conspicuous characteristic in the past. Of course, this was just the first shot, and there have been many changes in the company since we last saw it. Distinguished veterans, such as Mari Kajiwara, Dudley Williams, Marilyn Banks and others who were on view last night still glow with their accustomed luster, but on this initial glance the many newcomers didn't seem to be picking up on that old Ailey electricity in any consistent way.

On the other hand, the company has a formidable bounty of new repertory to show off with its return, including "Spectrum" by Washington's own Choo San Goh. Last night alone offered a quartet of Kennedy Center premieres -- two by Ailey himself and one each by Elisa Monte and Billy Wilson, all created since 1979.

The most compelling among them was, in a way, the smallest -- an inventive, sensuous, suspenseful duet by Monte called "Treading," set to one of those hypnotically repetitive "pulse music" scores of composer Steve Reich. Monte is a leading soloist with the Martha Graham company, but in earlier days she performed with the Pilobolus troupe, and "Treading," insofar as it bespeaks external influences, points more directly to the eccentric gymnastics of Pilobolus than the august psychologism of Graham.

The piece is exciting, though, precisely because it cuts loose from both forebears and finds a vibrant original vision of its own. In a pit of darkness, the nude-appearing body of Keith McDaniel writhes up from the floor, torso furling and rippling like some wild sea anemone. Mari Kajiwara, hidden in the shadows behind, slithers into view between McDaniel's bent thighs, and the two of them fold into each other's forms, venture into precarious balances, roll and spin and undulate until a final melting union in the returning blackness. It's all very carnal but not especially erotic in feeling. The title may be regarded as a sort of pun, because there's hardly a step -- in the conventional sense -- in the piece; the only treading is the kind you do in water.

Of the remaining works, two were set to piano concertos, and both seemed engaging, if modest, achievements. Ailey's "Landscape" uses Bartok's Third Concerto, in a musical but not slavishly subservient manner. Martha Graham was also among Ailey's one-time mentors, and the piece looks like a tribute to that fact of his history, not only in costuming (e.g., the women's long pleated skirts), but also in details of movement and the neoclassic disposition of the whole. There are some especially striking passages, such as the moment in the Adagio when the ensemble suddenly swirls off stage like raindrops on a pane.

Billy Wilson's "Concerto in F" has the Gershwin score of that name as its backdrop, and his mixture of classical ballet vocabulary with colloquial and jazz idioms reminds one a bit of Jerome Robbins, who happens to have choreographed the same concerto recently. In particular, the middle movement of the Wilson is like a miniature "Fancy Free"; instead of three sailors and two gals, Wilson gives us two buddies roused from indolence by a single flirt, in a concise witty exposition that leaves both men high and dry. The outer movements are brisk, busy and clever, for the most part.

The evening's one total clunker was Ailey's opening "Phases," set to a jazz me'lange. Overlong and tedious, it looked like a tired recycling of every Ailey cliche' on record, and even Dudley Williams' refined intensity in the finale couldn't give it a semblance of life.