This rather charming chap is Sir Herbert Hamilton Harty (good name). To Manchester, he was one of the most successful conductors of the Hallé Concerts Society. He was employed at the Hallé in 1920, the same year that this photograph was taken.
Here he is ready to perform at Glastonbury Festival. Not the Glasto of more recent legendary fame but the original Glastonbury Festival, founded in 1914 upon socialist, liberal and Utopian values in the arts. There's a rather lovely circular narrative to the story here: Glastonbury was chosen as the site for the festival because of its ties with the ancient legend of King Arthur. Harty is here dressed as Uther, fabled father of King Arthur, for the opera "The Birth of Arthur". This opera was written in 1909 by Rutland Boughton and Reginald Buckley who, in 1914, founded the Glastonbury Festival. Lovely.