Taken out of its natural environment, many an ethnic art form loses much of its spontaneity and significance. This is particularly true of ethnic dance. So many ethnic dance companies look out of place on a traditional proscenium stage. It's not only a matter of spotlights and microphones; it's that artificial barrier between performers and audience that does the most damage.

The National Dance Company of Senegal is one of the few ethnic ensembles that have managed to break down those barriers. Throughout 20 years of international touring, it has presented the traditional movement and music of its country in the most direct and heartfelt fashion imaginable. Rhythm is the source of all that it does, the language that allows for instant communication among the dancers and with the spectator. Because they understand how powerful these rhythms are, the performers avoid the gimmickry, painted smiles and cutesy stylizations to which so many companies succumb.

Each of the 32 performers who appeared Wednesday night on the stage of the Warner Theatre is both a consummate technician and an ambassador of goodwill. From the serene opening greeting to the frenzied finale, they summoned up an artistic heritage that is both ancient and absolutely contemporary. In "Khady Kebe," the story of a vivacious bride poisoned on her wedding day by her jealous stepmother, one watched a very believable community come to life by means of unison singing, polyrhythmic dancing and drumming, furtive glances and loving embraces. The virtuosic demonstrations of four traditional instruments -- the kora, balafon, dan and African flute -- left the listener with much the same sense of music made new as, say, a powerful solo by a tenor saxophonist or electric guitarist.

Even more visceral connections are made: When these uninhibited performers surge to the edge of the stage, or make their way into the aisles, it's almost impossible to resist joining those madly stamping feet and sinuously snaking arms and hands.

The company appears at the Warner through tomorrow. NOTES: 270-3879END NOTES