Gaelic cousin to the Inuit Eskimo vocal games - not so much Extremism of the Human Voice as just Extremely Delightful Human Voice.
More "Diddling, Lilting, Jigging, Chin Music & Cheek Music" at UbuWeb with the collection
Celtic Mouth Music - which originally came out in 1997 on
Ellipsis Arts - the company that also did that compilation of Mongolian throat song
Deep in the Heart of Tuva.
Oh, and what reminded me about "Diddlage" was this track on the excellent new
Kemper Norton album
Loor. Listen closely...