Styx built the foundation in October 1979 for what they hoped would be a brand new phase in a career that had already been underway for nearly a decade.

This was a calculated risk, as Styx simplified their oft-times highbrow material with pop-rock ingredients. Cornerstone would cause consternation among some die-hard fans, but the LP also led to the embrace of countless new ones.

Whatever side of the debate you may stand on, you really can’t fault Styx for going there. The Chicago-spawned quintet had achieved multi-platinum status on their own terms with previous art-rock efforts like The Grand Illusion and Pieces of Eight – their seventh and eighth studio LPs, respectively – while enduring the abuse levied at them by some critics.

READ MORE: The Best Tommy Shaw Styx Songs

Unfortunately, Cornerstone didn't solve that pesky little conundrum but it would allow Dennis DeYoung, Tommy Shaw and James "JY" Young an opportunity to stretch their songwriting talents and test the possibilities of mainstream radio.

So they threw themselves into the task at hand and duly filled Cornerstone to the brim with songs like "Why Me," "Never Say Never," "Eddie" and "Love in the Midnight," which notably dispensed with any hint of the complicated arrangements or cerebral wordplay found on prior Styx efforts.

Watch Styx's 'Babe' Video

Did 'Babe' Point to Things to Come?

Throughout, the tunes injected Styx’s familiar hard-rock foundation and instrumental prowess (underscored by the rhythm section of twins John and Chuck Panozzo) with incrementally catchy choruses, gorgeous three-part harmonies, loads of bright synthesizers and even saxophones.

Yet all this was merely the beginning for Shaw and DeYoung, both of whom decided to strike out in new musical directions. 

DeYoung applied his crystal-clear tenor to a birthday love letter to his wife Suzanne called "Babe," which promptly shot to No. 1 on the Billboard Hot 100. Meanwhile, Shaw whipped out a mandolin and broke things down to a folky and philosophical level on "Boat on the River," featuring DeYoung on accordion and Chuck Panozzo on double bass.

Despite the quality of song craft on display elsewhere, "Babe" became the album's defining song. But at what price? The single has since been unfairly pinpointed as the first sign of Styx's eventual fall from grace, even though both Young and Shaw had actually lobbied for its inclusion.

At the same time, backlash from the band’s prog-rock fan base was altogether mild. Cornerstone rose to No. 2, selling more than three million copies in the U.S. alone. There's a reason why: Dig deeper and you'll find this was – as promised – a Cornerstone release for Styx.

Rock's Ugliest Band Breakups

Ugly band breakups are a sad fact of life in the world of classic rock – along with death, taxes, hair loss and yes, profitable reunion tours.

Gallery Credit: Matthew Wilkening

Real-Life ‘Spinal Tap’ Stories: Styx

More From Ultimate Classic Rock