The Old Hall Manuscript (British Library, Add MS 57950) is the largest, most complete, and most significant source of English sacred music of the late 14th and early 15th centuries, and as such represents the best source for late Medieval English music. The manuscript somehow survived the Reformation, and formerly belonged to St. Edmund's College, a Roman Catholic school located at Old Hall Green (hence its name) in Hertfordshire. It was sold to the British Library after an auction at Sotheby's in 1973. Overview The manuscript contains 148 compositions overall, 77 of which are written in score rather than in separate parts. Most of the pieces are settings of parts of the ordinary of the Mass, and are grouped by section. In other words, the settings of the Gloria are together, as are the settings of the Credo, Sanctus, and Agnus Dei. Between these grouped settings are some motets and pieces related to the conductus. The Old Hall Manuscript was compiled in the early 15th century, probably over a period of about 20 years. The hands of several copyists are identifiable, and some of them may be those of the composers themselves. Recent research has suggested that work on the manuscript ended with the death of Thomas, Duke of Clarence, in 1421, a somewhat later date than was previously suggested. This date allows the fitting into the chronology of the most recent piece in the manuscript, the wedding motet by Byttering which was almost certainly written for the marriage of Henry V and Catherine of Valois on 2 June 1420, as well as a group of motets by several composers, the titles of which closely match written accounts of the music played at the celebration of the victory of Agincourt in 1415. Musical styles and techniques Various musical styles and techniques are represented including English discant, treble-dominated works, isorhythmic compositions, and canons. A complex Credo (No. 75 in the manuscript) includes a three-voice mensuration canon among its five voices; it is notated in black, red and blue notes. The Old Hall Manuscript is significant for confirming the existence and character of specifically English musical traits, the extent of the development of English music, as well as the influence of continental practices. In particular it shows a tendency in England to focus on musical complexities, such as canons, at a time when music on the continent was increasingly tending towards simplicity.