How many keys on a hurdy gurdy?

The hurdy-gurdy is a string instrument with a crank-operated wheel that rotates against the strings, causing them to vibrate and produce sound. The number of keys on a hurdy-gurdy varies depending on the instrument's size and design, but most have between 10 and 25 keys.

These keys are called tangents and are used to change the pitch of the strings, much like the keys on a piano. By pressing down on a key, the player raises or lowers the tangent, which in turn changes the length of the vibrating section of the string and thus changes the pitch of the note produced.