First Friday concerts at Christ Church. On May 3, at 7pm, internationally acclaimed organist Sandor Kadar, along with pianist Kira Boros, will offer solo and four-hand works of Bach, Franck, Widor, Dubois, and Hesse, Hungarian dances, and Easter-themed improvisations, all on the one-year anniversary of the installation of the Esther Wideman Memorial Organ, C.B. Fisk Op. 150. Free to the public, this special performance is not to be missed. Christ Church, Philadelphia, 2nd above Market St.