The Harp: Strings, Pedals, and Sonic Possibilities

The harp is one of the oldest instruments in the world and, at the same time, one of the most mechanically sophisticated. Strings stretched across an arched or angled frame appear in images from ancient civilizations such as Egypt and Mesopotamia. The modern concert harp, with its pedals and tuning discs, is the result of a long technical evolution that made it possible to play in any key with a single set of strings.

Structure of the concert harp

The modern pedal harp has three major structural elements. The soundbox is an elongated body with a thin wooden soundboard, where the strings are attached. The column is the vertical piece that bears the full tension of the strings and houses the rods of the mechanism. The neck (or crown), at the top, holds the tuning discs and the tuning pins.

The harp has 47 strings, covering about six and a half octaves. That number requires a sturdy structure, because the combined tension of all the strings is enormous. The instrument is therefore robust and weighs many pounds, so it calls for care in transport.

The strings are made of different materials depending on the register: gut or nylon in the middle and upper ranges, and metal-wound strings in the bass. To help locate notes, the C strings are colored red and the F strings black or dark blue. This lets the player navigate by sight, since the harp has no keys or frets.

The seven pedals and the tuning discs

The great innovation of the modern harp is the ability to change the pitch of each note. In 1810, the French maker Sébastien Érard patented the double-action mechanism, which remains the basis of the concert harp today.

At the base of the instrument there are seven pedals, one for each note name: D, C, and B on the left, and E, F, G, and A on the right. Each pedal acts on all the strings of that note in every octave, through internal rods connected to rotating discs in the neck. As a disc turns, its pins press against the string and shorten its vibrating length, raising the note by one or two half steps from the flat.

The pedals have three positions:

1. Top position: the string sounds flat, the lowest possible pitch for that note.
2. Middle position: the string sounds natural.
3. Bottom position: the string sounds sharp, a half step above natural.

The harp's open strings are tuned to C-flat major, and the pedals adjust the notes for other keys. This means the player changes the pedal positions with the feet during a performance, while the hands keep playing. That coordination is one of the greatest difficulties of the instrument.

Lever harps and other varieties

Not every harp has pedals. The lever harp, often called the Celtic harp, is smaller and lighter. On it, small levers near the neck shorten each string individually by a half step, but in one direction only. To change keys, the player has to stop and adjust the levers by hand.

There are also harps from regional traditions, such as the Paraguayan harp, widely played in Paraguay and other countries in Latin America. It usually has nylon strings, a larger soundbox, and a bright sound associated with popular styles. Each variety has its own technique and repertoire.

To see how the harp fits into the family of plucked strings, read about how plucked string instruments work, where the harp appears alongside other plucked instruments. The mandolin is plucked as well, but it uses a pick and paired strings, which give it a very different tone.

Techniques and sonic possibilities

The harp is played with the fingers, with no pick. The thumb and the next three fingers of each hand are used; the little finger is left out because it is too short. The fingers pull the string with the pad of the fingertip in a closing motion, producing a full, rounded sound.

Some characteristic effects:

• Glissando: sliding the fingers across a run of strings, creating a cascade of sound. With the pedals set, it can outline scales or chords.
• Harmonics: lightly touching the midpoint of a string to produce a high, crystalline note one octave higher.
• Damping: resting the hand or fingers on the strings to stop them from vibrating.
• Arpeggios: the notes of a chord played in sequence, a trademark of the instrument.

Because the strings keep ringing after they are plucked, the harpist has to damp them precisely to keep harmonies from blurring together. That care takes training and close attention to the score, which is written on two staves, like piano music.

Its role in the orchestra, and tuning

In the orchestra, the harp usually appears as one or two instruments, generally seated next to the string sections. It contributes tone color, arpeggiated chords, and smooth transitions. To see where it sits in the ensemble, consult how an orchestra is organized.

Tuning a harp is laborious. All 47 strings are tuned with a tuning key, and changes in temperature and humidity affect their tension, so the harpist usually tunes before every rehearsal or concert. A good foundation is to understand musical tuning and the role of reference pitches, since that is the logic you start from when adjusting each octave.

A brief history

The oldest harps recorded in paintings and reliefs were bow-shaped, with strings attached to a curved shaft. Over the centuries, the frame gained a front pillar, which allowed higher tension and more volume. In medieval Europe, the harp was cultivated at court and in folk traditions, and in the eighteenth century the first pedal mechanisms appeared, still single-action, which could raise a note only once. The double-action system of the early nineteenth century extended the instrument to all keys and explains its growing presence in symphonic repertoire from that century onward.

Where to Go From Here

Listen to a piece for solo harp and one for harp with orchestra, and notice how the same instrument can sound intimate or brilliant depending on the setting. If you would like to study it, ask a teacher to explain how the pedals work before you buy or rent an instrument. To reinforce what you have learned, test your knowledge in the quiz.