Rhiannon’s main appearances are in the First and Third Branches.
First Branch, episodes 1 and 2.
Second Branch, episode 6. Adar Rhiannon.
Third Branch, episodes 1, and by implication Episode 2. Episode 5.
Fourth Branch, episode 1 (Pryderi)
Culhwch ac Olwen. Adar Rhiannon as Bride Gift.
Lady of the Fountain, aka Owein: Birds of sweetest song, not referred to as Adar Rhiannon.
Rhiannon Gyda Theyrnon yng Ngwent, Hywel ap Goronwy.
Rhieinwg and Rheinwg. Slight similarity of names.
Llyfr Taliesin: Song Before the Sons of Llyr. (Manawydan, Pryderi.)
Llyfr Du Caerfyrddin: 31.20. (Manawydan)
Einion fab Gwalchmai, poem. (Pryderi)
Cynddelw, poem. (Pryderi)
Hywel Foel ap Griffri, poem. (Pryderi)
Trioedd: Adar Rhiannon not often heard. (Myvyrian Archaeology, Iolo Morgannwg forgery.)
(First published 01/12/2014: Shan Morgain)