Abbey Road — The Beatles (1969)

Abbey Road’s side-two medley, a 16-minute seamless suite of 8 song fragments, sells over 12 million copies worldwide, standing as the greatest pop songwriting achievement. Its $150,000 production cost in 1969 was 20% more expensive than the average Beatles album, yet it featured the band’s only Moog synthesizer, cheaper than typical experimental gear. The album outperforms #8 on this list for cohesive innovation, with 'Come Together' hitting #1 on Billboard.