The Buffalo Choral Arts Society has commissioned three custom medleys of Broadway and pop tunes to be debuted at their upcoming weekend performances of “An American Choral Celebration” (Friday, May 18 at 7:30pm and Sunday, May 20 at 3pm) at UB’s Lippes Concert Hall in Slee Hall. Under the direction of Marcia Giambrone, the chorus has grown to include the BCAS High School Master Chorale, inaugurated in 2006. Giambrone has strong roots in the field of music education, having been listed six times in Who’s Who Among American Teachers. She is now supervisor of student teachers at SUNY Fredonia. Giambrone has been with the BCAS since 1987, and during that time has led the group on three European concert tours and performed with the BPO and the Arts Nova Musicians, among others