'Dorian Gray is the subject of a full-length portrait in oil by Basil Hallward, an artist who is impressed and infatuated by Dorian's beauty; he believes that Dorian’s beauty is responsible for the new mode in his art as a painter. Through Basil, Dorian meets Lord Henry Wotton, and he soon is enthralled by the aristocrat's hedonistic worldview: that beauty and sensual fulfilment are the only things worth pursuing in life.
Newly understanding that his beauty will fade, Dorian expresses the desire to sell his soul, to ensure that the picture, rather than he, will age and fade. The wish is granted, and Dorian pursues a libertine life of varied and amoral experiences, while staying young and beautiful; all the while his portrait ages and records every soul-corrupting sin' (Wikipedia)
Described by its composer as a pure music drama of the modern school, the libretto, adapted from Oscar Wilde's novel The Picture of Dorian Gray (1890), was written in blank verse by W. J. Curtis and the dramatic organisation designed so as to afford scope for the dramatic and emotional changes needed to give freshness to the music ('Music and Drama.' Sydney Morning Herald 6 September 1919, p.8).
With regard to the score, the same critic writes:
Mr Orchard's prelude will open with soft chords for the lower strings, followed by a theme for the horn, reflecting the changeful Dorian's gloom and disenchantment. The next motif given pianissimo by the violins like a long drawn sigh will typify Lord Henry's darkly charming personality, and one of a more flowing character for violins will represent Sybil and foreshadow her distress. A strenuous crescendo for full orchestra will be divided by a few bars lull preparatory to a four not theme for the horns just as Dorian rises after his troubled sleep. These four themes form the kernel of the entire musical structure of the new opera throughout its three acts (p.8).