Joshua Gersen will be the guest conductor in two concerts performed by the Greenwich Symphony this weekend as the search continues for a permanent conductor. — This article is from GreenwichFreePress.com. The program will open with “The Golden Palace,” a celebratory, lively and joyful work from “Sun Warrior” by Eleanor Alberga. That will be followed Serge Rachmaninoff’s Piano Concerto No. 2, which Gersen described as one of Rachmaninoff’s most famous and popular pieces, and features what he described as a fiendishly difficult piano part.