Nun and musicologist who was an enthusiastic stalwart of Gregorian chanting

Mary Berry, also known as Sister Thomas More, who died on 1 May, 2008, aged 90, was a Catholic nun who split her time between practising her religion, teaching music at Cambridge and riving the Gregorian chant as a popular form of religious song.

She ran workshops, recorded CDs and advocated the ancient forms’ integration into liturgical worship.

She was a don at Cambridge where she founded her own school to teach and study the medieval music, and the professional singers within the school performed many pieces unearthed by Dr Berry.

Mary Berry was born on 29 June, 1917. She was the youngest of three sisters and her father was Vice-Master and Librarian of Downing College, Cambridge. Her mother was the daughter of a vicar and the household was Church of England.

Mary’s sisters attended university in Oxford but Mary chose to stay in Cambridge. "The music was better," she explained. She also went to Paris to studying under the renowned music teacher Nadia Boulanger.

Having developed an interest in sacred music, she was drawn to the Catholic church and received into the faith shortly before completing her music degree.

During the Second World War she nursed with the Red Cross in Belgium. There she joined a monastic order of Saint Augustine. When the German army advanced on the nuns, they were forced to flee to Paris and then Portugal where Mary saw out the war.

In 1945 she became a fully fledged canoness and became Mother Thomas More in religion. She taught and nursed in Rome before returning to France where she first taught chanting at the Institut Grégorien.

In 1963 she began a doctorate in musicology at Cambridge, taking Plainsong from the middle ages as the subject of her thesis. After this she was appointed director of music at Girton College and then made a fellow of Newnham College, all the while continuing her duties for the Church.

In 1975, she and a colleague, Rosemary McCabe, became disillusioned with the marginalisation of their art in the modern church. They set out to spread the word of "this wonderful, virtually unknown, music", founded the Schola Gregoriana and invited fellow enthusiasts to perform at St John’s College chapel.

Her zeal extended to dressing up in medieval costumes to enhance the experience and authenticity of the services. Soon word of her school’s chanting had spread and she was invited to teach and perform in Europe, America and Australia.

Dr Berry’s thorough research and tireless conduction saw the Schola become one of the leading exponents of medieval song and they recorded many pieces from primary sources – they were the first group of record music from the Winchester Troper, the oldest collection of Gregorian music manuscripts in Europe.

In 2000 she was awarded the Papal Cross Pro Ecclesia by the Pope and in 2002 she was given the CBE by the Queen for services to the music to which she dedicated her life.