Francesco del Cossa - or Angelo Macagnini.
Muses were daughters of Mnemosyne and Zeus, or, to other versions, daughters of Harmony, or of Uranus and Ge (Heaven and Earth). From the classical period the number of Muses was standardized to nine, and the following list was generally accepted: Calliope, the Muse of epic poetry; Clio, the Muse of history; Polyhymnia, the Muse of mime; Euterpe, the Muse of flute; Terpsichore, the Muse of light verse and dance; Erato, the muse of lyric choral poetry; Melpomene, the Muse of tradegy; Thalia, the Muse of comedy; Urania, the muse of astronomy. (Olga's Gallery)
Polyhymnia ("the one of many hymns"), in Greek mythology, was the Muse of sacred-poetry, sacred hymn and eloquence as well as muse of agriculture and pantomime. She is also known as the Muse of Mime. A very serious woman, pensive and meditative often depicted holding a finger to her mouth, dressed in a long cloak and veil and resting her elbow on a pillar. (Wikipedia)