For all the adjectives that could be applied to '70s progressive rock, "chill" and "mellow" are two that are pretty far down the list. As practiced by its most revered and cornerstone artists, prog rock excelled at being fussy, insular and complex. Lengthy, multi-part compositions built with jazzy and symphonic elements and employing highly technical instrumentation, prog rock at its most proggy demanded you pay attention to what was happening on the record, probably while respectfully stroking your chin in admiration.
This is not an ideal soundtrack for (real or imagined) California sunsets, chilled Riunite and Acapulco Gold, and looking deep into your old lady's eyes and exploring your feelings. Soft rock – with its laid-back vibes, simple instrumentation and achingly earnest lyrics – is what's best for that, and prog rock was about as far from soft rock as one could get in the '70s.
Except, you know, it wasn't all that far at all. A surprising (as in non-zero) number of prog artists dipped their toes into the warm and soothing Jacuzzi waters of '70s soft rock. Art-rock chameleons 10cc probably thought that the richly textured, multi-tracked "I'm Not in Love" fit in perfectly with the carnivalesque approach of their 1975 album The Original Soundtrack (which opens with a quite-proggy nine-minute "operetta"), but the blissfully laissez-faire song ultimately became something of a soft-rock anthem. Likewise for ex-Spooky Tooth member Gary Wright, who, in 1975, likely figured that "Dream Weaver" was a perfect showcase for his synthesizer abilities, but the song instead ended up soundtracking thousands of fern-bar pickups. (And yes, Spooky Tooth was best-known as a hard rock band, but they did record a prog-rock masterpiece in the form of a collaboration with Pierre Henry.)
Other esteemed progressive rockers like Todd Rundgren ("Hello It's Me"), Traffic co-founder Dave Mason ("We Just Disagree") and Rare Bird ("Passin' Thru") accidentally recorded soft rock gems, while arena-rock bands with progressive pasts or psychedelic bona fides – Jefferson Starship ("Miracles"), Styx ("Lady"), Chicago (all those Peter Cetera ballads) – scored big with the 'ludes-and-grooves set as they touched on different '70s styles.
Legendary producer Alan Parsons (Dark Side of the Moon) was decidedly prog in his approach to his solo career, with concept album after concept album containing suite after suite, but his only real hit was with the woozy and soft-rock-adjacent "Eye in the Sky" in 1982. But Parsons' biggest contributions to the soft rock canon were in the form of production work for the likes of folky prog-rocker Al Stewart ("Year of the Cat" and "Time Passages") and a band whose soft-rock success has completely eclipsed their robust prog-rock foundation: Ambrosia.
Due mainly to the group's heavy reliance on soaring harmonies, when Ambrosia focused on shorter and melodic songs, they struck soft-rock gold: "How Much I Feel," "Biggest Part of Me," "You're the Only Woman" and "Holdin' on to Yesterday" basically define the rock side of '70s soft rock. But it's important to remember that not only did they have Alan Parsons behind the boards for their first two albums, they were also a band decidedly focused on making intricate and complex progressive rock. Their 1975 self-titled debut had a song based on Kurt Vonnegut lyrics; the follow-up includes an eight-minute classical-pop suite ("Danse With Me George [Chopin's Plea]"); Life Beyond L.A. is a lyrically dense and multifaceted album that folds in hard rock, African rhythms, artful theatricality and, well, "How Much I Feel." It is, in other words, not an artist catalog that leans on the simplistic solipsism most commonly associated with soft rock.
And while their reputation (and current set lists) certainly reflects their dominance on yacht-rock playlists, Ambrosia serves as a wonderful reminder that, in the '70s, everyone – even the most devoted prog-rocker – was a little soft.