A harp is a stringed instrument, classified along with other instruments such as guitars and violins, as chordophones. There are several different harp designs which have developed over the years. A major type is the lever harp, in which the pitch of strings can be changed by twisting a lever at the top of each string. Another is the pedal harp in which this pitch can be changed using one’s foot. There are also cross-strung and double-strung harps, as well as instruments with more modern designs such as in-line chromatic, double in-line chromatic, and crossing triple harps.
There are no sharp or flat notes on harp strings unless they are specifically tuned to play them. One way to play sharps and flats is to use levers that change the string positions just enough to create the desired sound. Lever harp designs have small rotating levers at the top of every string, in the case of wire-strung harps. Any size instrument can incorporate such levers, but a harp player must stop briefly to change the pitch of the string, which can be a flat and natural note, or a natural and sharp one.
Pedal harps include pedals at the bottom that can be manipulated with the player’s feet, so both hands can continue plucking the strings. One pedal for each note is at the base, so there are seven which have three positions each. The mechanism that enables the pedals on these harp designs to control the string pitches is large. It runs from the base up the instrument’s column and over the top, so the instrument is much larger and heavier than a lever harp.
Cross-strung harp designs, built as early as the 1500s in Spain, have two sets of strings that intersect in the middle. One set is tuned diatonically and the other pentatonically. Harps like this do not need any pedals or levers because sharp and flat note variations can be played directly on the strings. Players can hit whatever note they wish with either hand as well.
Double-strung harp designs are in the same class and include two parallel rows of strings that are tuned the same way as a piano’s white keys. These kinds of harps are played the same way whether they are large or small. The left row is played by the left hand, and the right row is played with the right hand. Contemporary harp designs also include the inline chromatic harp, with all 12 strings per octave in a single row; and a double in-line 37+24 chromatic harp, the numbers corresponding to how many strings are in each row. There is also a crossing triple harp that has two parallel rows of strings with another row crossing them.