The masks represent two of the nine Greek muses. Tragedy is represented by Melpomene [mel-po-men-ee] and comedy by Thalia [thay-lee-a]. In Greek mythology, the nine muses were goddesses of the arts and sciences, and were daughters of Zeus, the king of the gods, and Mnemosyne, the goddess of memory. Melpomene, the goddess of tragedy, is usually shown holding a tragic mask, the club of Hercules and a wreath of vine leaves. Thalia, the muse of comedy, is depicted holding a comic mask, a shepherd's crook, and a wreath of ivy. The muses were worshiped throughout ancient Greece.