The 47 strings are tuned diatonically and produce the fundamental scale of Cb major. Every string therefore has a different pitch. The long (bottom) strings are near the foot, furthest from the musician, the short (top) strings near the neck, nearest the musician.
The harp is played in the sitting position, the upper part of the instrument’s body resting against the right shoulder. The foot rests on the floor. The instrument is played by both hands: the right hand plays the short strings, the left hand the long ones. Depending on the musical context both hands can be active over the entire range.
The strings are plucked in the middle with the fingertips. This is called striking. Striking the string in the middle produces the fullest sound. Près de la table denotes attack near the soundboard, which results in a sound that contains more partials, is brighter, more metallic and almost like a guitar.
Sons étouffés are notes which are damped by the flat of the hand.
Harmonics are produced by placing the ball of the hand on the middle of the string while the same string is plucked in the middle with the thumb.
When playing chords up to four notes per hand are possible. A reach of up to a tenth is normally possible, larger reaches are more difficult.
There is one pedal for each of the seven notes of the fundamental Cb scale. Each pedal can be depressed twice; depressing a pedal to the first notch raises the pitch of the corresponding string in all octaves by a half tone (the string is shortened): depressing it to the second notch raises the pitch a further half tone. In other words, the pitch of each string can be raised twice, each time by a semitone, which results in an increase of a whole tone.
Raising the Cb string to C with one pedal movement raises the pitch of all the Cb strings by a half tone; a second pedal movement raises all the Cb strings by a total of a whole tone. All the pedals work according to the same principle. It is not possible to change the pitch of one string only.
The notes Db in one octave and D in another are not playable, since only the Db string can be raised to D. The next lowest string, Cb, cannot be raised by three half tones. The same is true of the notes Gb with G and Ab with A. This means that the pitches D, G, and A can be produced on one string only.
1 Left foot
2 Right foot
3 Eb pedal
4 Retuning wires
5 Pedal positions
6 Normal position
7 Depressed once
8 Depressed twice
If the musician wishes to use, say, the pitches C and B in a glissando (both pitches should be playable at the same time with no pedal shift) he or she has two possibilities: either the Bb pedal is used to retune to B and the Cb pedal to retune to C, or the Bb is retuned to C and the Cb pedal is left in its original position.
Depressing all seven pedals at once retunes the fundamental key from Cb major to C major; depressing them all a second time raises the pitch to C# major.
Three pitches are available on every string, so 21 pitches are available from the seven steps of the diatonic scale. This means that almost every one of the twelve notes of the chromatic scale is available twice (2 x 12 = 24), with the exception of the three pitches D, G and A.
Notes of the same pitch which can be played on adjacent strings are also known as synonyms. Synonyms can be used for special combinations of scales and chords which are extremely effective when played glissando. A so-called bisbigliando effect (piano tremolo on two adjacent strings) also results.
It is therefore possible to play in all keys on the double-action pedal harp. Composers must give the musician time for modulations in distant keys (by using rests), because time is required to operate the pedals. It is for this reason that fast chromatic scales cannot be played on the harp. It is only possible to play excerpts of chromatic scales consisting of a few notes. These are used chiefly for embellishment.