Since forming in Berlin in 2000, The Ocean have been at the vanguard of progressive metal. Led by guitarist and composer Robin Staps, the German band is often referred to as The Ocean Collective, as nearly 40 members have passed through its ranks. Despite Staps’ ever-shifting lineup, the frontman’s ability to take listeners in unexpected musical and thematic directions—fusing elements of post-metal, sludge and the avant-garde while exploring themes as varied as Earth’s prehistory (2007’s “Hadean”), Christianity (2010’s “Firmament”) and oceanic depth zones (2013’s “Mesopelagic: Into The Uncanny”)—has never waned.