Sharon Wyrrick has established herself as one of Washington's deftest and most personable performers, and also as one of its most gifted choreographers. Her debut, with her troupe Full Circle, in the Kennedy Center's "Dance America" series Thursday night at the Terrace Theater, served not only to confirm these qualities but also to remind us of how attractively unpredictable she can be.

The two works she presented -- an extended solo and the premiere of a newly commissioned group piece -- showed her continuing her recent slide down the slippery slope of "performance art." That is, dance movement is increasingly subsumed into textures in which gesture, projections, props, lighting, costuming and music are in the ascendancy. The solo is a further exploration -- along lines she'd previously drawn -- of a fusion between intensely personal and public-global concerns. The group work, however, leaps off into heavy metaphysical territory that seems new for her both in means and content. The risk here was greater; if the solo seemed by far the more successful of the two, the group piece still prompted admiration for Wyrrick's audacity.

"Storyboard for an Anxious Journey: On the Cutting Room Floor," as the solo is named, is actually the middle portion of what has become a trilogy. "Tsunami" and "Where's the Milk?" were the earlier, also solo, segments of "Storyboard," premiered last year. In the new one, as in the older pair, Wyrrick talks as she moves among such props as a row of flowerpots, a stool and a small screen, mingling anecdotes of her own or her friends with news dispatches. The "Trees and Flowers" section of Carl Orff's "Music for Children" -- in which kids are heard in a rhythmic litany of botanical terms -- sporadically intrudes as aural backdrop.

The piece weaves a haunting chain of poetic associations, a meditation on the gulf between the natural and the synthetic. The act of cutting ties it all together in a typically idiosyncratic, Wyrrickish way -- from garden cuttings to heart surgery and artificial hearts; from film cuttings to the invention of celluloid as a substitute for elephant tusk; from frozen embryos to the cutting and splicing of human genes; and from there to computer-simulated tennis and other "virtual realities." Contemplating a future in which advancing technology may cut us off for good from contact with anything natural, Wyrrick ends her monodrama by reaching forlornly toward the clay pot that held a living rose at the start of the solo, but now holds only an empty stalk.

It's Wyrrick's charisma as a performer that makes the piece so effective. Her delivery is at once dispassionate and mysterious, giving the flow of imagery a dreamlike inner coherence. And she has, unlike some other dancers who turn to words, a fine elocutionary technique, compounded of her velvety, smoothly modulated voice and her clear, melodic diction.

If "On the Cutting Room Floor" plays out at the precarious edge of comprehensibility, "Cantiones Profanae" -- the premiered group work commissioned by the Washington Performing Arts Society (cosponsor, with Kennedy Center, of the "Dance America" series) -- drops into the abyss. This 55-minute opus, involving Wyrrick and the three women and one man of Full Circle, is a setting of Orff's choral song cycle "Carmina burana" (20 of its 25 numbers) that has no scenery, but vaguely medieval-looking garb. Unless, however, you are fluent in medieval Latin, or have memorized the liner notes for the Orff, you may find it, as I did, obscure in intention. There is a section, for instance, in which the dancers take turn folding themselves over a horizontally suspended pole; this may relate to a song having something to do, I think, with a roasted swan, but in what way and to what end is very unclear.

The piece opens strongly with Wyrrick in front of the curtain bound with ropes and gagged, trying desperately to communicate and then settling for inarticulate whooshings as the best she can manage. Toward the end of the piece, she frees herself from these bonds, and is escorted into the wings by the other dancers. In some sense, then, the work is about the struggle to discard shackles and blinders and win freedom of expression, but the details remain murky in the extreme.

The choreography has its striking passages -- one in which only the legs of the dancers are seen below a partly descended curtain; another in which they wrap themselves in skeletal bones and toss cards, dice and pennies onto the stage; and the finale, with the dancers trailing off into darkness whistling scraps of Orff's closing tune. But most of the movement is too generalized and indistinct to bear the weight of its symbolic baggage. And though the dancers -- David Bentley, Maria Costello, Barbara Chan and Denise Bell Read -- are more polished than those Wyrrick has worked with in the past, they don't quite give the movement the sharpness of contour or dramatic cogency it demands. In the end, the work also fails to reconcile the modest size of the dance ensemble and the bigness, even grandiosity, of Orff's score.

Wyrrick's muse has led her an erratic course in the past -- projects that sounded new depths followed by some that misfired. It's part of the price she pays for courageously striking out on new paths. She's always rebounded, and especially in recent seasons, given us a string of wonderful inspirations, such as the ambitious, four-part "Infinite Passions." Nothing about "Cantiones Profanae" suggests she's lost her touch, only that, as before, she may once again require some mid-course adjustments. Wyrrick has earned her place in "Dance America" with a wonderfully fecund imagination, and one would hope to see her there again.