Polyhymnia was the Muse of the sacred poetry
Polyhymnia(Polymnia) was the Muse of the divine hymns, the sacred poetry and the pantomime. She was also famous for inventing the science of geometry.
Polyhymnia is often depicted like a very strict and thinking deity, with a wrath of daphne in her hair, looking up to the sky and expressing herself with gestures while playing the lyre.