Calliope, Muse of Epics, is Melpomene's "Wing-Muse." She is equally devious and listens closely to her sister's direction. Calliope is a great role for an actress who can both sing and act well, and should be a perfect complement to Melpomene. For comedic effect, cast two actresses who look vastly different rather than identical. For example, it may be funnier to have a very tall Melpomene paired with a short Calliope or a Melpomene with dark hair with a Calliope with blonde hair.