The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, , at sacred-texts.com
p. 94 p. 95
The Birds of Rhianon sang until the Angels of heaven came to listen to them; and it was from their songs that were first obtained vocal song and instrumental music; vocal song being that which is sung by the lips to melody and harp.