The modern concert harp is very different in appearance from the instruments used centuries ago to accompany songs and from the instruments used today in folk music across the world such as the Irish harp, but the concert harp sound is very similar to that of its relatives only more powerful and richer in tone. All the other orchestral instruments are highly refined versions of their ancestors or folk relatives, but the beautiful droplets of sound that the harp produces have sounded similarly sweet for thousands of years.
Although the harp has a long history it was not really used in orchestral music until the 19th century. What brought this about was the development of a pedalling system, which enabled the player to continually change the tuning whilst playing, turning the harp into a fully chromatic instrument. The harp is not a particularly loud instrument but its sound of its attack does penetrate so composers often only use one with an orchestra or two with a larger orchestra.
As mentioned above, the harp relies on 7 foot pedals to change the pitches of its 47 strings. These pedals allow the harp to play chromatic notes but also means that composers need to be aware of leaving enough time for pedal changes
Composers tend to use harps in a variety of ways:
- to support harmonies by playing chords,
- to add definition to the start of notes, phrases or bass lines - by providing a little ‘ping' as another instrument begins to play
- and to create swirls of sound through glissandos – sweeping the hands across the strings in swift, flowing movements.
Because of the unique characteristics of the harp there are elements of the notation which are different, but essentially the harp is notated on two staves like the piano.