A tuning peg consists of a cylinder fixed to a round gear and allows
the player to change the tension in the string by rotating a peg. Tuning
pegs can vary such that some require more turns than others to achieve
one full revolution of the cylinder where the string is wrapped. This is
referred to as the gear ratio. Pegs with a higher gear ratio can allow us
to get a more precise tuning because they will require the peg be rotated
more to change the tune by the same amount in comparision to pegs with
a lower gear ratio.