Amongst the papers left by Manfred Bukofzer was a draft of an address to be given at the International Musicological Society's Con ference at Oxford in 1955¹ in which he identified two fragments, one from Cambridge² and the other from Oxford³ , as being the work of one scribe. To these Margaret Bent added another nine fragments, and in a paper presented at the 1972 IMS Conference at Copenhagen she argued that these eleven fragments were originally from the one manuscript, an English choirbook of the early fifteenth century, second in importance only to the Old Hall manuscript.⁴