Early 15th‐cent. coll. of church mus. found in the library of St Edmund's Coll., Old Hall, Herts., first described in 1903 and pubd. 1933–8. Sold privately to Brit. Library 1973. It offers a valuable opportunity of studying the choral style of a period c.1415. Comprises 140 folios of church mus. by composers of the Chapel Royal.