The nine Muses were the daughters of Jupiter and Mnemosyne, goddess of memory. They sang and danced to the lyre of their half-brother Apollo, god of (among other things) music.
Their inclusion here demonstrates how the Italian Renaissance re-integrated traditional culture and learning into Christian Europe. They are shown here in landscapes which may depict the Ferrara area of the time. All but Clio are wielding some sort of instrument, and all but Talia have an orb. Keep in mind that despite being casually described as “Muse of” one art or another, the Muses are a troupe; all proficient in song, dance, and poetry. Each of them also has multiple other roles.
XI Caliope
Calliope is the Muse of epic poetry; she was Homer’s Muse. She was also the mother of Orpheus, the great musician who returned from Hades after an unsuccessful attempt to bring his wife back from the land of the dead. Her gift is eloquence.
She stands blowing a long trumpet, while the wind blows her dress. Her orb is on the ground behind her. In the distance on the left is a city on a hill. On the right, a spring emerges from a pipe in a rocky hillside and flows into a basin. This is probably one of the two springs on Mount Helicon sacred to the Muses and said to be sources of poetic inspiration.
XII Urania
Urania is the Muse of astronomy and astrology; named after her great-grandfather Uranus. (Uranus, eponym of the first planet discovered in historical times, sired the first generation of Titans, who begat the Olympian gods). Urania brings deeper understanding of of the higher planes.
She stands in a landscape with cities on distant hilltops, next to a drying streambed. She is shown with her traditional accessories, a globe and compass, though the globe is usually depicted as full of stars.
XIII Terpsichore
Terpsichore is the Muse of dance; her name means “delight in dance”. According to some ancient sources, she was the mother of the Sirens. She plays her instrument so that others can dance; she brings delight.
Terpsichore is traditionally depicted playing a lyre. Here, she plays some sort of small guitar, standing at the water’s edge with a city on the far shore.
XIIII Erato
Erato is the Muse of love poetry, and also of mime; she brings charm. Traditionally depicted playing the lyre, here she dances and plays a tambourine.
XV Polimnia
Polimnia is the Muse of sacred song. She bestows eloquence and brings praise to writers. Her instrument in this engraving is a portative organ. She plays the keyboard with her right hand while working the bellows with her left. She was often depicted standing pensively.
XVI Talia
Talia, the Muse of comedy, is sitting on a bed of ivy playing a violin. In the background are olive trees, symbolic of her role as the inventor of agriculture. She is the only Muse depicted here without an orb; perhaps she’s sitting on it. Traditionally, her accessories are a Greek comedy mask and a short staff.
XVII Melpomene
Melpomene is the muse of tragedy. She was typically shown carrying a tragedy mask, and sometimes a sword. Here, she blows a hunting horn, while the wind whips her dress behind her.
XVIII Euterpe
Euterpe is the muse of lyric song. She is shown leaning against a tree playing her customary instrument, the double flute.
XVIIII Clio
Clio, Muse of History, rides the waters on a swan, her orb behind her. As she travels, she recites her story. The sash ends curling in the wind suggest the scroll with which Clio is commonly depicted.
XX Apollo
Apollo is unique among the Greco-Roman gods in being known by the same name in both cultures. He is here as the leader of the muses, but his actual role was far more extensive. We will meet him later, for example, as Phoebus Apollo, god and chariot driver of the Sun. Among his skills were music, archery, healing, and prophecy.
Here we see Apollo crowned and seated upon a throne of swans. Swans were sacred to Apollo; they sang when he played the lyre for the Muses, and carried him to the Land of the Hyperboreans where he spent his winters. He holds another of his attributes, a laurel branch. The story is told that the nymph Daphne turned herself into a laurel tree to escape his advances. At his feet is an orb containing both heavens and Earth.