Discussing his approach in performing Delius, Beecham wrote that "it is imperative to maintain a tight control over the motion of the melodic line: otherwise there may be created an unpleasant sense of lassitude or shapelessness."

Beecham said of Delius that he was a very unusual person; "he was a rebel, an independent, who described himself as a conservative anarchist. His music, once he had found himself, was largely underivative." He was, Beecham said, "the last great apostle in our time of romance, emotion and beauty in music."

Beecham considered that the best of Delius's music was to be found in the works where he disregarded classical traditions and created his own forms; almost all of these were his masterpieces which he wrote in the space of fifteen years, in the middle part of his life. Among them are Summer Night on the River and On Hearing the First Cuckoo in Spring; "in their respective ways they touch perfection." To Beecham, In a Summer Garden is flawless in both form and orchestration; its mood has a unity, and altogether in it lay the quintessence of the composer. A Song of the High Hills, wrote Beecham, "is the longest as well as his most impressive work written in a single movement. It is built on a heroic scale and the inspiration is on an exalted level throughout. The first entrance of the full choir singing as softly as possible is surely a stroke of genius, and of its kind without equal, either in him or any other composer".