Apollo's Lyre

Apollo's Lyre is a musical instrument invented by Hermes and given to Apollo as a gift.

History
The most wide known story is when Hermes was a baby he stole a number of Apollo's cattle and took them to a cave in the woods near  Pylos. In the cave, he found a  tortoise  and killed it, then removed the insides. He used one of the cow's intestines and the tortoise shell and made the first  lyre.

Hermes later gifted the lyre to Apollo in exchange for the cattle. The lyre then became one of Apollo's symbols of power.

Use
In Percy Jackson and the Singer of Apollo, Grover states that by playing the lyre one could create nearly anything. Apollo once used the power of his lyre to construct the walls of Troy.

Appearance
The base is a hollowed out tortoise shell, two polished wooden arms sticking out one side like bulls horns. A bar connects the arms at the top and seven strings stretch from the bar to the base of the shell. It looks like a combination, banjo, harp, and dead turtle.

Percy Jackson and the Singer of Apollo
When one of Apollo's back-up singers go rouge he charges Percy Jackson and Grover Underwood with the job of bringing her back. Apollo lends Grover his lyre saying it with help capture the automaton. He also warns them not to scratch it or else. When they finally spot the Celedon Grover attempts to create a brick wall around the Celedon but fails. Next he uses the lyre to create a bird cage and traps the Celedon inside when she transforms into a bird (dropping the lyre in the process). Percy and Grover manage to return the Celedon and the Lyre to Apollo before his concert. Apollo grows angry when he sees a scratch on his lyre but Percy claims "it'll buff out."