Closing next Sunday: Michael Pearce Donley and Peter Vitale are either very good piano players who act, or they are actors who are very good piano players. Either way, you benefit from their talents in this little show about keyboard whiz kids who learn the difference between being good and great. This is a charming show, with a particularly moving conclusion when Donley and Vitale perform Bach's D Minor piano concerto. (2 p.m. today and next Sun., 7:30 p.m. Wed.-Fri., 2 & 7:30 p.m. Sat. $25-$58. Park Square Theatre, 20 W. 7th Pl., St. Paul. 651-291-7005 or www.parksquaretheatre.org.)