Various designs of harp have been used in different places at different times. The Irish harp or clàrsach is linked to the medieval Irish and Scottish traditions, and modifications of these (sometimes given the name Celtic harps) were also developed during the nineteenth century. In Wales, a harp with three rows of strings became popular, and although originally developed in 17th century Italy, it subsequently became known as the Welsh triple harp. In Europe generally, from the 17th century onwards, diatonic harps and triple-strung harps were superseded by pedal harps - the single-action pedal harp being developed around 1720, and the double-action pedal harp in 1810. A unique design known as the chromatic/cross strung harp was also developed from the seventeenth century onwards.
Taking into account the dates of these various developments in relation to the period in which Mansfield Park is set (and the nature of the various harps), it seems reasonable to assume that Miss Crawford may have been the owner of a single-action pedal harp.
As the illustrations show, artistic depictions of female harpists in the early 19th century ranged from the demure to the humorous to the erotically suggestive.
Listen here to the melody Greensleeves played on the harp.