There is the air of classic prog, the songs' ornate, easily caricatured latticework—in Yes terms, the Jon Anderson and Rick Wakeman element. And there is the earth, their harsh, wiry skeleton—in Yes terms, the element of the late, great Chris Squire, along with Alan White and before him Bill Bruford. Anyone playing hard-hitting, compositionally daring rock music (math rock, tech metal, a million other microstyles) is, or ought to be, planting their ideas in the Squire soil.
The girth, the clarity, the metallic thwack of his bass tone. The bridge between, say, Mahavishnu Orchestra, where the bass typically took a backseat, and Rush, where it essentially became a lead instrument. For me, when Chris Squire's bass started to snarl and snap is the eureka moment when so-called prog became electrifying and essential, when geek brain met cyborg muscle. I'm not a Yes completist, but in the classic ’70s material, whenever the rhythm section starts to kick (and/or the Steve Howe visionary-shred roller coaster starts zooming around the track), it's a drop-everything moment for me.
Zero in on the riff that starts at about 6:04 in "Close to the Edge," the one with those thrilling syncopated Squire/Bruford stabs. It's all there. Props also to the monster mutant-funk groove at 6:51, with those grotesque melodic outbursts and chasm-like rests. Thank you, Chris Squire—you harnessed the low end, sacrificing none of its primal power, and made it dance and sing.