This word may originally have described a different stringed instrument, being etymologically related to the Welsh crwth.
It has been suggested that the word clàrsach / cláirseach (from clàr / clár, a board) was coined for the triangular frame harp which replaced the cruit, and that this coining was of Scottish origin.
On a low-headed harp the corr was morticed at the bass end to receive a tenon on the làmh-chrann; on a high-headed harp this tenon fitted into a mortice on the back of the làmh-chrann.
The strings, usually played with the fingernails, produced a brilliant ringing sound.
Scotland, because of her affinity and intercourse [with Ireland], tries to imitate Ireland in music and strives in emulation.
Ireland uses and delights in two instruments only, the harp namely, and the tympanum.
In Ireland and Scotland, it was a wire-strung instrument requiring great skill and long practice to play, and was associated with the Gaelic ruling class.
It appears on the coins and coat of arms of the Republic of Ireland.