The Lays of Beleriand
The Lays of Beleriand is the third volume of Christopher Tolkien's 12-volume series The History of Middle-earth in which he analyses the unpublished manuscripts of his father J. R. R. Tolkien.
The book contains the long 'lays' or poems Tolkien wrote in full: these are the Lay of the Children of Húrin about the saga of Túrin Turambar, and the Lay of Leithian (also called Release from Bondage) about Beren and Lúthien.
The first verse tale is in alliterative verse, and the second is in rhyming couplets. Both exist in two versions. In addition to these two poems, the book also gives some shorter, soon abandoned poems.
The first versions of the long lays fit chronologically in with Tolkien's earliest writings, as recounted in The Book of Lost Tales, but the later versions are close to the writing of The Lord of the Rings.