Although Holbrooke's choral writing could occasionally be unadventurous and somewhat four-square, as in the poem for chorus and orchestra "Byron", there are effects of startling originality elsewhere, ranging from the vocal use of the acciaccatura in "The Bells" to the multi-layered chorus of shouted warcries in the final act of "Bronwen". The solo vocal writing in the mature operas, whilst not strictly comparable with verismo, is generally declamatory and follows naturalistic speech-rhythms: in this sense at least, along with many of his contemporaries, Holbrooke was indebted to Wagner although his musical idiom is more dissonant. Indeed, from the 1920s onwards his music gained a noticeably increased harmonic astringency: