These early U.S. dates include: Train Kept a Rollin', I Can't Quit You Baby, As Long As I Have You, Dazed and Confused, White Summer / Black Mountainside, How Many More Times.

Led Zeppelin make their American debut on this date, as they begin a short string of shows, the first few unbilled, opening for Vanilla Fudge.

It was Dec. 26, 1968, and Fey had sold out a Vanilla Fudge and Spirit concert in the Denver Auditorium Arena - what's now part of the Ellie Caulkins Opera House.

"About 10 days before the show, I got a call from the agent saying, 'Barry, I want to add an act to our show,' " Fey said. "I said, 'Ron (Terry), all the tickets are sold.'

"He said, 'You've got to do this for me, Barry, this is a big, big act. Their name is Led Zeppelin.' I thought it was a joke."

Fey turned Terry down, until the agent showed Fey the money.

"Ten minutes later Ron called back and said 'Vanilla Fudge is going to give you $750, and if you give $750 of your own money, we still can put Led Zeppelin on the show.' " Fey caved in. The concert crowd had no idea that this new heavy-metal band from Britain was added to the show. That night marked the band's American debut.

"I got up on the stage and said, 'Ladies and gentlemen, give a warm Denver welcome to Led Zeppelin,' " Fey said. "They started playing, and it was incredible. It was an unbelievable show; people were gasping. That was a big day in Denver history." (Rocky Mountain News)