A rare double-bill featuring Led Zeppelin and the Who - the only time this would occur. The encore featured another early appearance of Whole Lotta Love. Some 8mm backstage footage of both bands together exists, as well as a clip of Zep's performance.

"Zeppelin's thumping set was running long however, and an unlucky member of The Who's crew was tasked with moving things along. "I had the unenviable task of throwing Zeppelin off the stage," recalled Jeff Wolff. "They were playing over time, stringin' it out, and there was a curfew, so I was saying, 'I've got to get you off!' I had to pull the plug on them, otherwise we were never going to go on!" (from Anyway Anyhow Anywhere - The Complete Chronicle of The Who: 1958-1978, by Andy Neill and Mark Kent).

Press Review:  At the Merriweather Post Pavilion in Columbia, MD, on Sunday night, comedian Uncle Dirty, Led Zeppelin and The Who performed to a packed hall, field and parking lot. Led Zeppelin played a fairly orthodox show, mostly using material off their first album. And although guitarist Jimmy Page once again proved himself a fine musician, there wasn’t much more to be said about the act as a whole. He and singer Robert Plant launched into innumerable transgressions of tonal question-answer games, more conducive to boredom than musically induced languor.[R. Cowan]