Erato's instrument was the LYRE, a four-letter stringed instrument. The LYRE is one of the oldest known instruments and is believed to have originated in ancient Mesopotamia. It was associated with the Greek goddess Erato, the muse of lyric poetry, and was used by the ancient Greeks to accompany their songs and poems. The LYRE was also used in religious ceremonies and was often seen in the hands of Apollo, the god of music.