The opening notes on Yes' 21st studio album are like sonic comfort food: Guitarist Steve Howe teases an ethereal melody, his delayed notes conjuring the mystical waterfalls and hovering spaceships of any good Roger Dean cover. But the blissful vibe is temporary -- moments later, Geoff Downes enters with a blaring synth pad, while new frontman Jon Davison stretches awkwardly into cosmic goo.

But just when you're ready to write off opener 'Believe Again' as a lukewarm retread, the chorus arrives, bassist Chris Squire anchoring Davison's feather-light cries with an earthy warmth; then midway through, Howe unleashes a sinister guitar break, punctuated by Downes' fusion synth squalls. In eight minutes flat, the track manages to frustrate and delight in equal measure -- exemplifying the overall half-excellence of 'Heaven & Earth.'

The high points here rank among Yes' finest work in decades -- but reaching those heights is never easy. 'The Game' is as solid a straight-ahead pop song as they've written since '90125,' riding a wordless vocoder hook and a lovely guitar fade-out -- but it's marred by a vague, hippie-dippie lyrical style and a paper-thin drum sound that might as well be looped from a Casio. The acoustic ballad 'To Ascend' wastes Howe's yearning 12-string and lovely harmonizing from Squire and Davison, weirdly transitioning to a bouncy, anti-climactic new-age chorus ("Taking the time on a wing and a prayer / A wounded bird in the hand / With the eyes of a child / Come to understand").

The songs -- most of the time -- aren't the problem; it's the way they're captured on tape. Roy Thomas Baker, the man who once helped Queen realize their most grandiose sonic visions, doesn't aim too high on 'Heaven & Earth,' offering the band a computerized sheen that doesn't fit their organic, muscular strengths. The album was supposedly written and recorded on a tour-looming time crunch, and it often sounds like it: Alan White's drums are often surprisingly loose, and a few sections (the timpani-synth intro to 'Subway Walls,' the chorus piano on 'To Ascend') feel stitched together and slightly out-of-synch, suggesting the players were never in the same room together.

The only skippable track here is 'In a World of Our Own,' a clumsy attempt at low-key blues-rock that kicks off with the lyric "What's wrong with the new revolution?" and only gets more cliched from there. One taste of "You can whet your appetite anywhere / As long you do your cookin' at home" and you'll beg for the "Caesars Palace, morning glory" days of 'Yours Is No Disgrace.'

It's no surprise that the LP's highlights are more epic in scope, with flowery arrangements and plenty of instrumental fireworks. 'Light of the Ages' is a shape-shifting gem, built on a lush Howe steel guitar that pings into the atmosphere. And the grand finale, the nine-minute 'Subway Walls,' is the band's finest prog epic since 'Machine Messiah' all the way back on 1980's 'Drama.' It evolves from classical-quoting filigrees to math-funk madness (partially in 17/8) to a galloping coda with Squire and Davison harmonizing the word "Transcend" like two knights charging into battle.

Yes, 'Heaven & Earth' has its issues -- it's often tentative and sonically flat. But it also proves that, 47 years into their singular career, they're still capable of greatness.

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