MARK MORRIS ENSEMBLE AT ROYCE HALL

The first thing you notice about Mark Morris’ choreography is its spatial authority--the way each piece definitively establishes its style and scale in an opening image. Next, you’ll probably be surprised by Morris’ movement vocabulary: a slippery admixture of folk, ballet and modern- dance influences plus an irrepressible infusion of dramatic gesture. And you’ll soon see how Morris’ scrupulous musicality gives even his ventures in off-the-wall humor a disarming formal rectitude.

But beyond these skills and virtues, beyond all the particulars that critics isolate, is the truth upon which Morris’ quick rise to prominence in the dance world has been based: He makes choreography look easy, natural, a medium of hit-and-run immediacy. At 31, he creates works of great daring and vitality--qualities matched by his 12-member company and evident throughout a five-part program at Royce Hall, UCLA, on Thursday.

Every section of the octet “My Party” developed with formidable ingenuity from a different linear premise--a chain of dancers, a circle, a double line, etc.

Every section also imaginatively reflected the capering passage work of Jean Francaix’s buoyant String Trio through playful, bouncy steps, shifting positional relationships and even brief outbursts of floor wrestling. Morris has long been candid about being a homosexual artist and his integration of same-sex partnering as an compositional element here proved characteristically forthright.

At one point, an especially fancy unison in the score yielded a sudden eruption of chugga-chugga shoulder spasms, as if Morris’ dancers were spontaneously moving to this music the way other young Americans move to rock ‘n’ roll.

In the same manner, the sophisticated architectural gambits of “Marble Halls” were expressed in idiosyncratic flurries of running and hopping, dodging and kicking, creeping and falling. But by prolonging and intricately synchronizing these simple activities, Morris made them both a major test of his 10 dancers’ prowess and an exciting, post-modern reflection of Bach’s Concerto for Two Harpsichords and Strings in C minor.

Similarly, he used simple walking steps, stark friezes, startling jumps, whiplash back bends and a few sequences of more conventionally dancey movement in his quintet “Fantasy” to suggest the weight and depth of Mozart’s somber Fantasy in C minor. The result (again): An unmistakably American, wholly contemporary statement of connection to our European cultural heritage.

For his satiric “Deck of Cards,” Morris created spectacular solos for himself (in drag as the archetypal Guilty Woman), Donald Mouton (as a half-dressed military man making a demented display of his piety) and a remote-controlled toy truck, demolishing in the process the three preposterously inane and/or hyper- macho country ditties used as accompaniment.

Seen in the Morris company’s 1986 program at Cal State Long Beach, “One Charming Night” again showcased the extraordinary versatility of Morris and Teri Weksler in initially elegant but increasingly grim and violent courtship dances set to songs by Purcell.