Instrument
Harp
A plucked string instrument tuned by foot pedals, not fingering.
The harp belongs to the string family in the broad sense - it makes sound from vibrating strings - but works quite differently from the bowed instruments around it. Its strings run vertically and are plucked directly with the fingers, and pitch is changed not by pressing strings against a fingerboard but by pressing one of seven foot pedals.
How the pedals work
A concert harp has 47 strings. With every pedal in its middle position, they sound the white notes of a piano - a scale with no sharps or flats. Each of the seven pedals controls every string of one note name (all the Cs, all the Ds, and so on), and each pedal has three positions: flat, natural, and sharp. By setting the pedals, the harpist tunes the whole instrument to a particular key, and changes the settings with their feet as the music moves. To help find their place, the C strings are colored red and the F strings black or dark blue.
That pedal mechanism makes the harp less harmonically flexible in fast passages than a keyboard instrument, which is part of why composers tend to use it sparingly and specifically - for shimmering arpeggios, delicate accompaniment, or a distinctive splash of color - rather than as a constant presence the way strings or woodwinds are used. Its most famous effect is the glissando, a sweep of the hand across the strings.
An ancient instrument, a modern design
The harp is one of the oldest instruments in the world; elaborate harps and lyres survive from ancient Mesopotamia, more than four thousand years ago. The modern orchestral (or "pedal") harp, with its full chromatic pedal system, was developed in the early 1800s - the instrument maker Sébastien Érard patented the double-action pedal mechanism in 1810. Earlier harps, including many folk harp traditions still played today, use simpler tuning systems without that pedal mechanism.
In the orchestra
Most orchestras have one or two harpists, called on when a score asks for them. Romantic and Impressionist composers loved the harp's color: Berlioz used two harps for the ball scene of his Symphonie fantastique, Tchaikovsky gave it a dazzling solo in The Nutcracker, and Mahler scored the famous Adagietto of his Fifth Symphony for strings and harp alone. Debussy and Ravel wrote some of the instrument's finest music.
Essential harp music
- Handel - Harp Concerto in B-flat, Op. 4 No. 6.
- Mozart - Concerto for Flute and Harp (1778).
- Debussy - Danses sacrée et profane (1904), for harp and strings.
- Ravel - Introduction and Allegro (1905), for harp, flute, clarinet, and string quartet.
- Britten - A Ceremony of Carols (1942), for treble voices and harp.
Where to start listening: the harp glissando (a rapid sweep across the strings) that opens Tchaikovsky's Waltz of the Flowers is one of the instrument's most recognizable orchestral moments. For the harp as a soloist, Mozart's Concerto for Flute and Harp is pure elegance.