Through his leadership role with the Three Choirs Festival, Sumsion maintained close associations with major figures in England's 20th-century musical renaissance, including Edward Elgar, Herbert Howells, Gerald Finzi, and Ralph Vaughan Williams.
Although Sumsion is known primarily as a cathedral musician, his professional career spanned more than 60 years and encompassed composing, conducting, performing, accompanying, and teaching.
'[1] When Sumsion's treble voice broke at age 15, he became an 'articled pupil'[a] to Brewer, a designation connoting a three-year apprenticeship in organ, choral direction, and music theory.
As one of Brewer's articled pupils Sumsion was following in the footsteps of his slightly older contemporaries, Herbert Howells and Ivor Gurney.
Sumsion's duties during this period included serving as accompanist for the Three Choirs Festival Chorus, which occasioned a brief but memorable encounter with Elgar after a rehearsal of The Dream of Gerontius.
[1] Sumsion earned an undergraduate degree in music from Durham University in 1920 and continued in his post at Gloucester until 1922, when he embarked for London to become organist of Christ Church, Lancaster Gate.
The Curtis Institute was then a conservatory in its infancy, but figures such as Leopold Stokowski, famed conductor of the Philadelphia Orchestra, were associated with it in its early days.
Emmie Morris wrote frequently to her sister Adeline (who was married to Ralph Vaughan Williams) and reported 'with interest' on Sumsion's courtship of an American girl, Alice Garlichs.
On 1 March 1928, Herbert Brewer died suddenly of a heart attack, leaving the post of organist at Gloucester vacant only a few months before the cathedral was to host the Three Choirs Festival.
[10] After the retirement in 1949 of Percy Hull of Hereford and Ivor Atkins of Worcester, Sumsion remained the only direct link with Elgar amongst the musicians of the three cathedrals.
Sumsion maintained personal friendships with many of the well-known composers who frequented the festival, particularly Vaughan Williams, Finzi, and Howells.
[7] Concurrent with his post at the cathedral Sumsion served as director of music at Cheltenham Ladies' College (1935–1968) and directed the Gloucester Choral and Orchestral Societies.
Sumsion's compositional style reflects the influence of his more famous contemporaries Howells, Finzi, and Vaughan Williams,[7] while at the same time retaining something of the 'diatonic strength' of Edwardian composers like Parry and Brewer.
Works such as the Magnificat and Nunc dimittis in G major, the Preces and Responses, and the anthem They that go down to the sea in ships have entered the standard repertoire of Anglican church music.