More than 250 quatrains of love and loss, the texts to those inimitable flamenco performances - these are the songs that are wailed by those keening male voices, as the red-and-black-clad women dancers stamp, pirouette and fire castanet rhythms at machine-gun pace. Not high art certainly, but a part of deeper fabric of the real Spain, and a powerful influence on poets such Lorca.
Various is the correct author for any book with multiple unknown authors, and is acceptable for books with multiple known authors, especially if not all are known or the list is very long (over 50).
If an editor is known, however, Various is not necessary. List the name of the editor as the primary author (with role "editor"). Contributing authors' names follow it.
Note: WorldCat is an excellent resource for finding author information and contents of anthologies.