Who wrote and sang the 1973 hit "Piano Man"?

Billy Joel

What mountain was home to the Greek gods and goddesses? Which twins, children of Zeus and Leda, are known together as the Dioscuri? What traditional Mexican sweet bread is typically served during Día de los Muertos? Which gluten-free grain-like seed is traditionally grown at high altitudes in the Andes mountain region? Who sang the hits "Shake Your Body" and "Blame It On the Boogie"?