During Tuesday's The Late Late Show, the talk show host ignited a friendly feud when he claimed there's been a lack of new hits this summer.
"Whenever I turn the radio on now, all I'm getting are slow, boring ballads. Do you know what I mean?" Corden ranted. "I want to roll down the windows, I want to jam out. No one wants to hear some guy on a guitar crying about his girlfriend in the middle of the summer."
"It just feels wrong," he continued. "Seriously, who would want to listen to a ballad when you could listen to a great summer bop? They’re so boring."
Legend then arrived onstage to interrupt Corden's statement, receiving a warm welcome from the studio audience.
"I heard you've been telling people bops are better than ballads," the GRAMMY-winning singer exclaimed. "I feel attacked. It feels, like, kind of personal."
"For me, summer’s a time to slow things down,” he added. "How about we settle this, right here, right now?"
Legend then jokingly declared war, and the bops versus ballads Riff-Off officially began.
Round after round, the pair took turns singing a cappella with the Filharmonic to back them up. Corden started the battle with the Jonas Brothers' hit single, “Sucker," and Legend came back with the smooth All-4-One classic, "I Swear."
The comedian later redeemed himself with a hilarious rendition of Billie Eilish’s “Bad Guy.” Yes, the lyrics "seduce your dad type" came out of Corden's mouth.
Nonetheless, it was basically over for Corden once Legend blew the competition away with his own song, "All of Me." The audience sang along in full support.
Corden admitted Legend was the clear winner, but the record producer took the high road and found a middle ground.
"Maybe there's a world where the song of the summer is a ballad. We could combine the bop and the ballad," he offered.
Legend and Corden eventually settled their differences for good by mixing bop and ballad elements on the Lewis Capaldi track "Someone You Loved."
Back in May, ET spoke with Legend backstage at The Voice, where he opened up about his fellow coaches "hating" on the popular competition show's cross battles.
"I knew the show was different and had a different format before. I think the other coaches didn't like it, because they wanted more control on narrowing the teams down before we let the fans vote," Legend explained. "I can see the wisdom in that."