X:1 % T:Rotha's Lament T:Cumha Rotha L:1/8 M:3/4 S:Fraser Collection (1816) Z:AK/Fiddler’s Companion K:Eb (GF)|E2z2z2|c4 (BG)|[G,3E3] FGE|C4 B,2|E2z2z2| c3d e2|G3A F2|[G,4E4G4]:|(3Bcd)|e3 fef| d3 ede|c3 dcd|B3 cdB|e3 fge|d3 efd| c3 (d/e/ f/e/d/c/)|c4 [EB] (=Bc/4G/4A/4F/4)|E2z2z2|c4BG|[G,3E3] FGE| C4B,2|[B,2E2]z2z2|c3de2|G3A F2|[G,4E4G4]||
ROTHA'S LAMENT (Cumha Rotha). Scottish ("Supposed Welsh," says Fraser), Slow Air (3/4 time). E Flat Major. Standard tuning (fiddle). AAB. "This air the editor supposed to be Welsh. He acquired it several years ago from a young lady who could give no account of it, nor has he heard it with any other since nor has it appeared among the Welsh melodies. The editor has since tried to associate it by means of the name, and its being a lament or dirge, with any traditional or historical event belonging to the Highlands; but failed of success, till the first proof copy that was put into his hands of Albyn's Anthology, which contains an air of the name, but bearing no similarity to this one, giving a description of a steed, not unlike Don Quixotte's Rosinante, on which a hero belonging to Argyllshire, or rather Mull, whose title was Totha, or Rutha, sallied forth. Though the proof copy contained such an air, it is not brought forward in the principal; yet, from the name belonging in this manner to Argyllshire, at which the editor only glanced, he is hopeful the air to which this note alludes may also be traced to Argyllshire" (Fraser).
The melody is sometimes characterized on the internet as a 'Welsh folksong', but other than Fraser's statement about its 'supposed' provenance there is no evidence it was connected with Wales.