Charles Guard's album "Avenging & Bright" (Shanachie, 1991) has a tune called CRAOBH NAN TEUD (LAMENT FOR THE LOST HARP-KEY).

Alison Kinnaird's album "The Harp Key" (Temple Music, 1978, reissued 1996) has a tune called CUMHA CRANN NAN TEUD (THE LAMENT FOR THE HARP KEY).

Authorship is credited to Rory Dall O'Cahan, "Blind Rory", an Irish harpist of the 17th century.

I can't explain the difference in the titles, since I don't know a word of Gaelic, either Irish or Scots.