Following the full-blown psychedelia of In Search of the Lost Chord, The Moody Blues' sound evolved into the Mellotron-gilded progressive pop style that became their signature. Psych-soaked traces pop up, like the trippy vocal effects on "Dear Diary," and there's even a touch of country rock on "Send Me No Wine." But for the most part, the Moodies' fourth album offers soaring melodies, angel-choir harmonies, pop hooks, and a Mellotron-supplied orchestral feel. The lyrics draw on everything from Arthurian legends to Eastern philosophy, filtered through a flower-child sensibility.