Twyla Tharp graduated from Barnard in 1963, and she's still showing love for her alma mater. Ms. Tharp's "Treefrog in Stonehenge," an exuberant ensemble romp that debuted last year, joins the New York City Ballet veteran Robert La Fosse's ode to George Balanchine and Andrea Miller's ode to Doris Humphrey at the college's spring dance concert. (Ms. Tharp also delivers a lecture-demonstration on April 26 at 4:30 p.m. Reservations, which are required, can be made at dance.barnard.edu.) Also on the bill is "Lamentation Variations," an ode to Martha Graham's influential 1930 solo.