Despite his relatively late arrival on the scene, Sumsion's leadership of the 1928 Three Choirs Festival at Gloucester impressed both music colleagues and the press. In those days the resident organist bore the burden of conducting, and though in 1928 several composers were on hand to conduct their own works—notably Elgar and the Hungarian composer Zoltán Kodály—Sumsion was responsible for works such as Verdi's "Requiem" and Honegger's "King David", the latter being a Three Choirs debut. It was following the 1928 festival that Elgar made his oft-quoted pun: 'What at the beginning of the week was "assumption" has now become a certainty.'