Fleetwood Mac, 'Tusk' (1979)
Costing a cool million to record, making it the most expensive rock production to date, Fleetwood Mac's double-vinyl successor to the hugely successful Rumours was, as creative spearhead Lindsay Buckingham told Rolling Stone, "clearly an undermining of what was expected of us." Where Rumours was packed with immediately affecting tracks polished to a high studio luster, Tusk experimented with a sleazier lo-fi sound and ad hoc production twists — and where Rumours topped the Billboard 200 for 31 weeks to sell more than 20 million copies, Tusk peaked at Number Four before eventually selling some four million albums. The intragroup emotional dysfunction and romantic anguish the Mac explored on Rumours continued, but this time Buckingham matched the emotional chaos with makeshift percussion, proto-punk guitars and a Stevie Nicks who never sounds the same twice. Mirage's soothing soft rock returned the Mac to the top of the charts three years later.