Thomas Ravenscroft, the English composer, editor, and arranger, is known for his participation in the St. Paul's Boys' Choir, as instructor of music at Christ's Hospital School, and as a prodigy. His best-known publications are a setting of the psalter, The Whole Booke of Psalmes, and the treatise, A Brief Discourse,which is an effort to revive mensural notation. Ravenscroft's works contain many examples of popular Elizabethan music which he edited and arranged. Part II of this thesis consists of an edition of his third publication, Melismata, a collection of nine rounds and fourteen partsongs. A list of critical notes is also included. The commentary to the edition includes a biography, a discussion of his works, the background and origin of the songs in Melismata, and an analysis of these songs.