In the early 1920s William Walton, still a teenager and barely on the first leg of his composing career, caught the attention of the formidable glitterati siblings, the Sitwells. “Adopted” into the family, he was encouraged by the poet sister, Edith, to collaborate with her on a thoroughly modern piece of theater. The result was Facade, which startled the audience when it premiered in 1923, but is now considered one of the most engaging works in English music. A caustic wit with a keen ear for the nuances and cadence of the English language, Sitwell supplied the 21 poems–some nonsensical, some mordant, some provocative, all marked by an insouciant sense of humor. Walton proved himself a fastidious craftsman adept in idioms ranging from fox-trots and tangos to jazz and Gilbert and Sullivan patter songs. In Facade his music provides a richly hued kaleidoscopic backdrop for Sitwell’s inimitable sensibility (which has been called highbrow Noel Coward in some quarters). The poems are spoken in tricky rhythms, and for this presentation the noted baritone John Shirley-Quirk and Lady Susan Walton, the composer’s widow, have the honors. They will be accompanied by the Chicago Pro Musica, the Grammy-winning chamber music consortium. Facade is seldom revived here–which makes this production even more special. The performance benefits the William Ferris Chorale, certainly one of the better choirs around. Friday, 8 PM, Chicago Cultural Center, 78 E. Washington; 527-9898.