Members of Led Zeppelin, from left, John Bonham, Robert Plant, Jimmy Page, pose with singer Sandy Denny after receiving their awards in the Melody Maker Pop Poll in London, England, in September 1970. 

AP Photo

The day after Christmas 50 years ago, unsuspecting Denverites received a belated gift: The first North American performance by Led Zeppelin.

The then-unknown British band hadn't even released an album yet when they opened for Vanilla Fudge at the Auditorium Arena on Dec. 26, 1968. A music critic for The Rocky Mountain News described their performance as, "the full routine of mainstream rock done powerfully, gutsily, unifiedly, inventively, and swingingly."

Colorado music historian G. Brown talked to Colorado Matters about the significance of the band's performance. Brown runs the music archival site the Colorado Music Experience.