Unlike other types of stringed instruments, such as violins and violas, harps are played without the use of bows. The strings on a harp are designed to be plucked or grazed with the fingertips. There are several different types of strings for the wide variety of harps available. Manufacturers produce harp strings from different materials, including nylon and copper; they are available in lengths designed to fit various types of harps.
Wire-strung harps are strung with wires constructed from a variety of metals. Copper, brass, and bronze are a few of the more popular metals used in the construction of harp strings. Even certain precious metals such as silver are manufactured into harp strings. Metal strings are not nearly as flexible as nylon strings, but they are more durable and last longer.
Monofilament nylon harp strings are typically available in a limited range of colors including red, black, and blue. Nylon strings are the ideal strings for most types of harps. They are flexible, relatively easy to install, and traditionally cheaper than metal strings.
The strings on a harp must be positioned a minimum distance apart to allow ease of use and to prevent them fromtouching one another. Positioning strings too close together may also promote excessive vibration, resulting in a buzzing sound. While smaller harps are usually designed for use with just one type of string, larger models are often fitted with several different types of strings to achieve a certain range of sounds.
Lever harps employ a lever system that increases their range, adding the ability to play flat and sharp notes. Attached to a lever, a string can be used to produce two different notes. A switched lever shortens the effective length of each string, allowing a different pitch to be produced when plucked. These harps offer the benefit of producing a broader range of sounds from a limited number of strings.
Pedal harps feature pedal systems instead of levers to achieve different sounds from strings. These harps typically include seven pedals that each operate in one of three adjustable positions. Pedals moved into their middle positions do not affect the notes produced by a string, but pedals in their topmost positions produce flat notes and pedals in their lowest positions, producing sharp notes. This type of harp offers the benefit of not requiring the user to employ his or her hands to produce a flat or sharp note, but the added mechanical components required of these harps makes them much bulkier and heavier than most lever harps.
Irish harps are traditionally wire-strung harps that employ metal strings. The term “Celtic harp,” however, refers to any harp that grew out of the Celtic tradition. These harps are traditionally lever-type harps that use nylon, wire, or gut strings. Double-strung harps, meanwhile, are generally designed for use with nylon strings.