28. The harp is one of the oldest of instruments (dating back over 6000 years), but it is only in comparatively recent years that it has been used in the symphony orchestra. Its range is from
to
.
The modern double-action harp has forty-six strings, which are tuned in half-steps and whole-steps so as to sound the scale of C♭ major. It has a series of seven pedals around its base, each pedal having two notches below it, into either of which the pedal may be lowered and held fast. The first pedal shortens the F♭ string so that it now sounds F, (giving the key of G♭); the second one shortens the C♭ string so that it sounds C (giving the key of D♭); the third pedal shortens the G♭ string so that it sounds G (giving the key of A♭); the fourth changes D♭ to D (giving the key of E♭), and so on until, when all the pedals are fixed in their first notches, the scale of C is sounded instead of C♭ as was the case before any of the pedals were depressed. But if the first pedal is now pushed down into the second notch the original F♭ string is still further shortened and now sounds the pitch F♯ (giving us the key of G), and if all the other pedals are likewise successively lowered to the second notch we get in turn all the sharp keys—D, A, E, B, F♯ and C♯, the last-named key being obtained as the result of having all the pedals fixed in their second notches, thus making all the tones of the original C♭ scale a whole-step higher so that they now sound the C♯ scale.