Led Zeppelin were on the rise in the summer of 1969, while Doors frontman Jim Morrison was in the midst of a long and painful public downward spiral. On July 27, the two bands met going in opposite directions.

Both acts were scheduled to perform during the final day of the Seattle Pop Festival, a three-day rock extravaganza that also included appearances by Santana, the Guess Who and Chicago, among many others. Unfortunately for Doors fans, Morrison didn't much feel like entertaining the crowd by the time his band took the stage.

According to the book Jim Morrison: Life, Death, Legend, the crowd seemed "bored" with the group's performance of "When the Music's Over," setting the stage for what became an open confrontation between the singer and the audience. "He tried rapping to them during 'Light My Fire' and someone threw a cup of beer at him," recalls the book. "Jim gave him the finger. Someone else cursed him and Jim let fly: 'Hey, hey, hey — you bigmouth bastard, say that again. Get it all out — all your little hatreds, everything that's boiling inside you. Go ahead — LET ME HAVE IT!"

Unsurprisingly, the kids in the audience did as they were told, resulting in a set that may have been sickly fascinating from a non-musical point of view, but ended in shambles, with Morrison reportedly striking a crucifixion pose for three solid minutes after the rest of the Doors had cleared the stage. As far as Zeppelin singer Robert Plant was concerned, it made for an appalling spectacle.

"You can get into a trip of your own that you don't really realize what's going on in the outside world," Plant later told Melody Maker. "He hung on the side of the stage and nearly toppled into the audience and did all those things that I suppose were originally sexual things, but as he got fatter and dirtier and more screwed up, they became more bizarre. So it was really sickening to watch. My wife and I were there watching and we couldn't believe it."

Watch the Doors at the Seattle Pop Festival in 1969

Zeppelin took the stage after it all ended, and according to one critic at the show, they delivered a suitably satisfying palate cleanser for the wary crowd; as the review put it, "Sunday night was supposed to belong to the Doors but it was stolen right out from under them by the great English blues group, Led Zeppelin ... Zeppelin faced a jaded and uncomfortable audience that had been standing in the cold all evening. But the electricity of lead singer Robert Plant and guitarist Jimmy Page quickly warmed them up."

Sadly, Morrison would only continue to intensify his unpredictable behavior during the rest of his short tenure with group, and died less than two years after the Seattle debacle. For Plant, who'd been a fan prior to the show, watching him in action proved to be a bitter disappointment. "I respected the Doors' albums," he insisted. "What Morrison was doing on record was good. The track 'Cancel My Subscription' was great. He was just miles above anyone's head."