World War I was a traumatic time for Bridge, an ardent pacifist. One can hear more dissonance and darkness creeping into such works as the Cello Sonata in D minor (1913-1917) and the Quartet No. 2 in G minor (1915). After several years of near-silence, Bridge's next big work signaled a large shift in style. The Piano Sonata (1921-1924) was written in memory of composer Ernest Farrar, who was killed in action in France, in 1917. In it, one hears considerably more dissonance, abrupt changes of mood and tempo, and a more angular and aggressive sound. This stylistic evolution continued in works like the third (1926) and fourth (1937) string quartets, which flirt with Schoenberg-like atonality. In his last two decades, Bridge composed, occasionally conducted, and did some traveling, including trips to the United States in 1923, 1934, and 1938. He also did some private teaching. Certainly his best-known pupil was Benjamin Britten, who was an 11-year-old prodigy when Bridge met him in 1924. Britten retained a great affection for his teacher, and paid tribute to him in the Variations on a Theme of Frank Bridge (1937), based on the second of the latter's Three Idylls for String Quartet (1906). Britten was also partly responsible for the subsequent interest in Bridge's music.
Among Bridge's later compositions were a lovely opera, The Christmas Rose (begun 1919, set aside for years and completed only in 1930), as well as several important chamber and orchestral works. His last completed composition was the Rebus Overture (1940); he also left a symphony for strings unfinished at his death.