In 1883, George Moore collaborated with his brother Augustus in 'doing the book' for an English version of 'Les Cloches de Corneville,' with the help of Jimmy Glover. Their otherwise unrewarded toils provided material A Mummer's Wife. The poster is from the first Paris production in 1877.
Moore acquired a more serious interest in music through his friendships with Édouard Dujardin, editor of Revue Wagnerienne, and playwright Edward Martyn (a devotee of Palestrina, then Wagner).
Martyn tried to get Moore to come along to the Wagner Festival in Bayreuth in August 1893, but it seems Moore did not go. Pearl Craigie brought him to a Wagner concert in London in May 1894, and the following summer Moore went to Bayreuth (he was there with Maud Burke, later Lady Cunard). Thereafter, he was a convert, and returned to Bayreuth, again with Edward Martyn.
Wagner's life, his relationships to women, and to Nietzsche & Schopenhauer became the fascination of Moore's intellectual life. They formed the germ of his novel Evelyn Innes (1899).
The Melodic Line
Moore's interest spread from music itself to the creation of 'the melodic line' in narrative. See Stoddard Martin, 'George Moore and Literary Wagnerism,' in From Wagner to 'The Wasteland' (1982) and George Moore Across Borders (2013).
But not alone Wagner. Moore was also soon a follower of the fashion of early music played on the original instruments. As did Yeats and Shaw, he visited Arnold Dolmetsch in Dulwich, a suburb south of London, where Dolmetsch and his daughters recreated, according to old patterns, lutes, psalteries, and other traditional instruments. Dolmetsch too has a part in Evelyn Innes.
When Moore came to collaborate with Yeats on Diarmuid & Grania, Moore wanted modern music. In 1901 Edward Elgar was commissioned to compose an overture and interlude, possibly the most lasting outcome of that collaboration.
To provide the music for The Passing of the Essenes (Arts Theatre, London; 1 October 1930) the 78-year-old Moore turned to the cutting-edge composer Gustav Holst.