If you have a chance to attend an orchestra concert anytime soon and one of the pieces on the program calls for a harp, make sure to watch the harpist’s feet. They’ll be busy. The modern concert harp has forty seven strings, but it also has seven foot pedals, each of which controls one set of strings for each note of the scale. The A pedal, for example, controls all the A strings on the harp, and can change their length so that they sound A-natural or A-sharp or A-flat. As they play, harpists