there are seven pedals on a concert harp. each pedal can be in a high, middle or low position. the strings of the harp can be thought of like the white notes of a piano, tuned to naturals (c,d,e etc.). each pedal can change one of the letter-named notes one semitone higher or lower. for example: the pedal on the left changes all the ds to d flat (if the pedal is in the highest position) or d sharp (in the lowest position). from left to right the pedals operate the ds, cs, bs, es, fs, gs and as.