The William A. Calder Equinox Concert Series honors Professor William A. Calder's legacy as a professor, musician and citizen at Agnes Scott from 1947 to 1971. At the time of the Fall and Spring equinoxes (the September and March Open Houses), the gathering features a concert given by a visiting musical group or solo musician. Following the lecture or concert, guests are invited to stay for a planetarium show and (weather permitting) observations with Observatory telescopes, including the historic Beck Telescope. Planetarium shows typically include fun astronomy facts and a look at what is visible in the local sky that night.

Dr. Corey Flowers is a guitarist and composer currently based in Lawrenceville, Georgia. He holds teaching positions at Agnes Scott College, Piedmont College, and with the UGA Community Music School. In addition to classical pursuits, Corey also writes and performs rock/metal music featuring a blending of styles, extended range instruments, mixed meters, virtuosic soloing, and intricate rhythms.