The company returns to its roots with a program called “Cool Vibrations.” Robert Joffrey first toured with his troupe in 1956 with the express purpose of delivering American-style ballet to the masses. In 1973 he commissioned a piece from talented unknown Twyla Tharp, who used music by the Beach Boys. Deuce Coupe is the earliest of the three “pop” dances on this program–and a landmark in the world of ballet, putting the frug, the swim, and the monkey onstage. Laura Dean’s 1993 Sometimes It Snows in April, set to three Prince songs, is less aggressively radical. The opener to the Joffrey’s evening-length Billboards (which included three other choreographers), it has a soft, flowing quality well suited to ballet, especially in the first section, set to the raggedly sung but heartfelt elegiac ballad the piece takes its name from. The third work is a world premiere: Donald Byrd’s Motown Suite, set to music by Martha Reeves & the Vandellas, the Supremes, and Marvin Gaye, among others. Byrd is known as the choreographer of The Harlem Nutcracker and The Color Purple, the latter currently running on Broadway. Opens Wed 4/26, 7:30 PM. Through 5/7: Fri 7:30 PM, Sat 2 and 7:30 PM, Sun 2 PM, Auditorium Theatre, 50 E. Congress, 312-902-1500, 312-386-8899 for groups of ten or more, $15-$125.