Musical instrument in which strings, sounded by plucking, run between a neck and a sound box (also called the body or resonator). The strings run perpendicular to the sound box (instead of parallel, as on a guitar).
Harps are made in three basic shapes: arched harps, in which the neck and body form a bowlike curve; angular harps, in which neck and body form at least a right angle; and frame harps, in which a third piece, the forepillar, is placed opposite the angle between the neck and body, forming a triangle, to brace them against the tension of the strings. The modern orchestral harp is a large frame harp having 46 strings (six and one-half octaves, with 7 strings per octave); the bass strings made of covered wire and the treble strings of gut or nylon. To produce accidentals (sharped or flatted notes) lying outside the harp's seven-note scale, the instrument has a system of seven double-action pedals, each pedal controlling one string in every octave. The harp is tuned to the C-flat scale; when a pedal is depressed one notch, each string it controls is raised by a half step, as from C flat to C natural; when it is depressed two notches, each is raised a whole step, as from C flat to C sharp.
Arched harps, the most ancient of all harps, were known in Sumer and Egypt between about 3000 and 2000 BC, and angular harps appeared somewhat later. Arched harps survive today in Myanmar (formerly known as Burma), in parts of Africa, in a few areas of Siberia, and in an isolated part of Afghanistan. Angular harps were prominent in medieval Arabic and Persian music and were played as late as the 19th century in Persia. Frame harps, almost exclusively European, appeared by the 9th century and developed in two versions, one used in Ireland and Scotland, and one on the Continent. The Irish harp, like its Scottish counterpart, was a powerful instrument with a broad, deep sound box hewn from one block of wood; a thick, strong neck; and a heavy, curved forepillar. Strung with 30 to 50 brass strings that were plucked by the player's long fingernails to produce a brilliant, ringing sound, it survived in Irish aristocratic circles until about 1800. Medieval harps in other parts of Europe were smaller and lighter, with about 7 to 25 strings, apparently of metal, and narrower, shallower sound boxes. By about 1500, gut strings came into use, and a taller form developed, having a straight forepillar that could support more string tension than a light, curved forepillar. This Gothic harp is the ancestor of the folk harps of Latin America and of the modern Irish and orchestral harps.
As music in the 16th to 18th centuries gradually demanded more notes lying outside the seven notes of the European harp's scale, attempts were made to enable the harp to produce the additional notes. These included adding a second row of strings tuned to the sharps and flats (chromatic harps), setting small hooks on the neck that could be turned to catch a string and raise its pitch a half step, and providing pedals to which the hooks (or later, rotating disks) were connected by levers and wires set inside the forepillar. Devised in 1720, the first single-action pedal harp could raise the pitch of the selected strings by a half step, allowing the harp to play in many, although not all, keys; this was achieved with the double-action harp developed in 1810 by Sebastien Erard in Paris.
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