Sutton Foster will star as Nurse Fay Apple in the Encores! revival of Stephen Sondheim and Arthur Laurents’ little-seen 1964 cult musical, “Anyone Can Whistle.”Foster’s Broadway credits include lead roles in “Thoroughly Modern Millie,” “Shrek,” “Young Frankenstein,” “The Drowsy Chaperone” and “Little Women.” Running for five performances April 8-11, the concert staging gives New York auds a chance to hear one of Sondheim’s most underappreciated scores. A satire of conformity and nonconformity in early-’60s society, the show was a legendary flop on Broadway, closing after only nine performances. That original production starred Lee Remick and Angela Lansbury. The 2009-10 Encores! season opens with George and Ira Gershwin’s “Girl Crazy,” running Nov. 19-22, followed by Harold Rome’s “Fanny,” adapted by S.N. Behrman and Joshua Logan from the Marcel Pagnol trilogy. That show runs Feb. 4-7.