September 18, 2017 Leaf 1 1. A Choirbook leaf This hymn is dedicated to Saint Hilarion whose life story was written by Jerome in 390 at Bethlehem. The leaf contains many marginal notations in a later ca. 16th c. hand. It employs the stave of 4 lines usually attributed to an Italian Benedictine Monk called Guido of Arezzo (approx. 991-1033) and is a useful resource for music notational history. Leaf 2 Leaf 7