Kalathos krater (small wine-mixing vessel), 470 B.C.

Sappho and the poet Alcaeus each hold a barbiton (an instrument like a lyra) and a plectrum to pluck the strings of their instruments in their hands. The scene might refer to a competition between the two poets at a festival of Dionysos.

More about Sappho, Dionysos and the Greek mythology: http://www.perseus.tufts.edu