PITTSBURG, Kan. — Spring is a time of transformation, and can be displayed in a number of ways. Pittsburg Ballet will present its Spring Showcase at 7 p.m. Thursday, May 19, in Memorial Auditorium to show the community how the dancers have developed their skills since the fall. Owner of Pittsburg Ballet, Yana Feldman, said that a showcase like this stems from Russian ballet culture in which students perform for teachers and parents to prove they have learned the skills necessary to advance to the next level.