Cross-strung harp

The cross-strung harp is a multi-course harp that has two rows of strings which intersect without touching. While accidentals are played on the pedal harp via the pedals and on the lever harp with levers, the cross-strung harp features two rows so that each of the twelve semitones of the chromatic scale has its own string.

The first cross-strung harp is believed to have been created in the late 16th century in Spain and was known as the arpa de dos órdenes. Its identity as an instrument was established as soon as the early 17th century and it was used in both liturgical and secular music. Its popularity reached its peak in the late 17th century, and declined thereafter into the early 18th century. The reasons for its decline are complex, including the cultural displacement of Spanish music and musical instruments at court (such as the arpa de dos órdenes and the vihuela) in favor of Italian and French music and instruments (violin, harpsichord, lute, etc.).

The Pleyel & Wolff Company in Paris produced a cross-strung model based on pedal harp proportions in the late 19th century, to try to accommodate increasing chromaticism in orchestral music (a problem for orchestral harpists, because of the single-action pedal system still in use on orchestral harps). Designed by Gustave Lyon and known as the harpe chromatique, it had two sets of strings, one tuned to C major and the other tuned to F-sharp/G-flat pentatonic like a piano, enabling the harpist to play any note from either side of the neck. The two sets of strings crossed near the vertical midpoint of the strings, unlike those of the arpa de dos órdenes, which crossed close to the neck. This allowed both of the player's hands to reach both sets of strings at the point of greatest resonance.

Perhaps the most famous classical composition written for the harpe chromatique is Claude Debussy's Danse sacrée et danse profane for harp and strings, commissioned by Pleyel and published in 1904.

There was a developed in the late 19th century that found only a small number of proponents, and was mainly taught in Belgium.

Towards the end of the 19th century, the English-born American harp builder Henry Greenway built several copies of his peculiar cross-strung chromatic harp model featuring X-shaped pillar and two necks. One of them is displayed at the Metropolitan Museum in New York City and another at the National Music Museum, Vermillion, South Dakota.

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Wikipedia