Inglis states that almost every account of the significance of "Sgt. Pepper" emphasises the cover's "unprecedented correspondence between music and art, time and space". The cover helped to elevate album art as a respected topic for critical analysis whereby the "structures and cultures of popular music" could henceforth justify intellectual discourse in a way that – before "Sgt. Pepper" – would have seemed like "fanciful conceit". He writes: ""Sgt. Pepper" cover has been regarded as groundbreaking in its visual and aesthetic properties, congratulated for its innovative and imaginative design, credited with providing an early impetus for the expansion of the graphic design industry into popular music, and perceived as largely responsible for the connections between art and pop to be made explicit."