Classic Wiki

The harp is any plucked string instrument, usually triangular in shape, in which the plane of the strings is perpendicular to the soundboard. Zithers, auto harps, guitars and violins all have their strings running parallel to the sound board (or sound hole), which is their major difference from harps.

Although harps come in a huge variety of shapes, sizes, and weights, they all consist of three main parts: the sound board (or box), the neck, and the strings. The modern Western harp is triangular in shape. Most harps are between two feet (60 cm) to six feet (1m.80) tall and have 22 to 47 strings. Smaller harps may sit on your lap, but larger ones usually rest on the floor. Their strings may be of gut, wire, or nylon, in one, two, three, or crossed ranks.

Source harpspectrum.org

The harp is one of the world's most ancient and universal instruments; two facts possibly associated with the simplicity of its earliest forms. (Simplicity is definitely not a quality associated with the construction or performance technique of the modern harp.) Basically, the earliest harp-form was a conjoining of two frame parts; the body and the neck, between which were strung various lengths of gut that were then plucked to produce notes of differing pitch.

The earliest harps can be traced back well into antiquity, even as far as 3000BC. These earliest types were arched harps and angular harps. The framed harp from which the modern orchestral harp derives eventually joined them.

Source classicol.com

Edmar Castaneda harp solo youtube video