The Celtic harp is a triangular harp traditional to Brittany, Ireland, Scotland and Wales. It is known as a telenn in Breton, cláirseach in Irish, clàrsach in Scottish Gaelic and telyn in Welsh. 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.

The early history of the triangular frame harp in Europe is contested. The first instrument associated with the harping tradition in the Gaelic world was known as a cruit. 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 was coined for the triangular frame harp which replaced the cruit, and that this coining was of Scottish origin.

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