The orchestral scores display a virtuosity of instrumentation which owes much to Elgar and Richard Strauss, reaching a peak in works such as "Queen Mab", "The Bells", "Apollo and the Seaman" and "The Children of Don". From his early maturity onwards, Holbrooke evinced a sophisticated appreciation of orchestral tone-colour, using several unusual instruments in his scores including the concertina ("The Bells"), sarrusophone ("Apollo and the Seaman"), saxhorn and saxophone (Serenade for oboe d'amore, clarinet, basset horn, two saxhorns, viola, five saxophones and harp). His reputation for using outlandish instruments and inflated orchestral resources is, however, generally undeserved: most of his large-scale works are scored for the modern symphony orchestra as used in the early twentieth century. Hannen Swaffer, a writer for "The Graphic", referred humorously to Holbrooke on several occasions as "The Cockney Wagner", although the only real similarity between the two was a predeliction for mythological music drama: