"May the Friendship between Chinese and American Peoples be Everlasting!" proclaimed a banner unfurled during last night's Warner Theatre performance of the Jiangsu Song & Dance Troupe from the People's Republic of China.

From this beginning, seduction was the essence of this program: the performers combined broad, cheery demeanors with nonstop winning smiles. And, for insurance, the repertory was de'tente-based, including, in addition to traditional Chinese songs, touching and unusual performances of such American favorites as "Oh, Susannah," "Jingle Bells," "Yankee Doodle" and "Home on the Range." What sounds like overkill worked. If foreign policy were left to this audience, relations with China would immediately jump from somewhat strained to hearty.

The repertory of this company, on its first visit to the United States, represents various areas of China in a blend of folk, classical and contemporary work. The folk dancing is exuberant and includes some of the virtuosic acrobatics familiar from visits of the Chinese opera groups. The contemporary work, represented by "Sea Wave," is a me'lange of modern, ballet and acrobatic, emphasizing, as did the music on the program, the imitation of nature. "Burying Falling Flowers," the elaborate classical offering, is a Chinese "Swan Lake": A "white corps" surrounded a sorrowing heroine who was supported in turns and extensions by a secondary male partner. Li Sha, who danced the heroine, has a back that arches so exquisitely it would be the envy of Ginger Rogers.