Mary Berry, CBE (Sister Thomas More) (29 June 1917 – 1 May 2008) was an Augustinian canoness and noted choral conductor and musicologist. She was an authority on the performance of Gregorian chant. John Rowlands-Pritchard was a pupil of John Stevens at Cambridge, and gave lecture demonstrations of Professor Stevens’ isosyllabic interpretation of mediaeval monody. He studied the performance of early chant with Dr. Mary Berry, illustrating her lectures and broadcast talks, and sang and recorded regularly with her specialist group Schola Gregoriana of Cambridge as Cantor, and continues to give masterclasses in Plainchant across the country for the RSCM.