Cholly Atkins, the man who created all the original Motown "moves," will emcee Rhythmicity, the North Carolina Youth Tap Ensemble's annual show in Durham this year. The 88-year-old Atkins will also be putting on a workshop open to the public. The choreographer has worked with all the greats, from The Temptations and Gladys Knight, to Smokey Robinson and The Supremes. (Atkins is pictured above coaching teenager Aretha Franklin, then a new artist at Columbia Records, ca. 1960.) The ensemble itself, made up of dancers primarily from the Triangle area, features 30 exuberantly tapping young people, aged 6-18. Their two-hour tap program includes smooth interludes as well as heart-stopping percussive romps, ranging from South African gum boot dancing and Irish step dancing, to contemporary improvisation. Cholly Atkins' "Vocal Choreography" Motown class will be held at the Ballet School of Chapel Hill Saturday, April 20, from 1:30-2:30 p.m. The N.C. Tap Ensemble's Saturday show will be at 7 p.m., and the Sunday performance will be at 2 p.m., at the Carolina Theatre in Durham. Call 560-3030 for details.