by 1945, brain was the most sought-after horn player in england. he was 24 years old at the time. his father injured himself in a fall and lost much of his stamina to play. after the war, walter legge and sir thomas beecham founded the philharmonia and the royal philharmonic orchestra, respectively. brain filled the position as principal horn in both. along with jack brymer (clarinet), gwydion brooke (bassoon), richard walton (trumpet), terence macdonagh (oboe), and gerald jackson (flute), he was a member of the "royal family" of wind instrumentalists of the royal philharmonic orchestra. later, he found that he did not have enough time to fill both positions and resigned from the royal philharmonic orchestra.