In 1920 Dyson was thirty-seven years old. After his traumatic war experiences, his self-questioning about the direction of his future work, and his need to settle down and build a stability which had been so lacking throughout the past six years, his thoughts turned to teaching again. The need for stability was emphasised by the birth of his daughter Alice. The post of Director of Music at Wellington College in Berkshire became available and he decided to apply. He was appointed in 1920 by the headmaster, William Vaughan, who was looking for someone to breathe new life into what he considered to be a moribund department. As David Newsome writes in his history of Wellington College, Vaughan ‘had never been satisfied with the state of College music. Alan Gray, Fox Strangways and Tomlinson had struggled manfully with the old organ …’ Much of Vaughan's dissatisfaction seems aimed at the state of the old chapel organ. Another historian of the College, R. St. C. Talboys, noted that ‘It was a console of the primitive kind, and little better than a harmonium.’ Amusingly he painted the picture of its being ‘worked by water mysteriously beneath ground … [and that] it was liable to attacks of asthma, which sometimes resulted in total silence. But the school sang on, unsupported and undismayed.’

Talboys also reported that ‘Music was not greatly encouraged, though at concerts it did break through.