What are sharping levers?

Loveland Sharping Lever

Sharping levers are mechanical devices that are installed on harps to facilitate key changes.

Folk Harps are diatonic instruments and can only play in one key without re-tuning.   Pedal harps, or orchestral harps, use a complex pedal mechanism to change keys.  Folk harps use the much simpler sharping lever.

A sharping lever can be placed on each string on the harp.  As the name implies, a sharping lever will raise the pitch of the string by one half step.   A harp with a complete set of sharping levers can play in any key without re-tuning.