By contrast, musicologist Daniel Harrison contends that Wilson's advancement as a composer and arranger was marginal in relation to his past work. He wrote that "Pet Sounds" shows "comparatively little advance from what Brian had already accomplished or shown himself capable of accomplishing. Most of the songs use unusual harmonic progressions and unexpected disruptions of hypermeter, both features that were met in 'Warmth of the Sun' and 'Don't Back Down.'" Granata referred to "Pet Sounds" as the culmination of Wilson's songwriting artistry, although his "transition from writing car and surf songs to writing studious ones" had already "exploded in 1965".