Apollo's Lyre or Kithara, is a musical instrument invented by Hermes and given to Apollo in exchange for the Caduceus. It was often seen accompanying Apollo or the Muses. Apollo was given the epithet "Citharoedus". The most famous statue of Apollo Citharoedus (Kithara-playing Apollo) is in the Vatican Museum.
The kithara was played with a plectrum and generally had seven strings. The modern word "guitar" is derived from kithara. In Modern Greek, "kithara" has come to mean guitar.