When the National Socialists came to power he was obliged to leave Germany (since his father was Jewish) and settled in England in 1935.
He became assistant to music director Karl Rankl and conducted there many times from June 1947 onward.
[8] As a young man in Berlin, Gellhorn was already composing, examples being the four movement Kleine Suite for oboe and piano (1932) and the String Quartet No 1 (1933-4), both in a highly chromatic though still tonal style.
But also in 1937 he composed the more introverted and melancholy Intermezzo for violin and piano, written for his friend Maria Lidka.
[11] This melancholy vein continued with his first setting of English words (by Walter de la Mare): Autumn (1938).
His later works include Thoughts on a Chinese Tune for two clarinets and piano duet (1976), the Dialogue for violin and viola with string orchestra (1977), a second Trio Suite, for children (1982), and a final song, Aedh wishes for the Cloths of Heaven (1995).