Here's three quarters of an hour of Led Zeppelin slightly before the O2 reunion. It's for Earls Court in 1975, to be exact. You have to love YouTube. Most of my life it would have been almost impossible to show someone not actually in my house a video of something worth watching. This YouTube video expands to full TV screen and looks great.
Don't be annoyed by the way the video starts off with mandolins and acoustic guitars - that's the way Led Zeppelin were. Unlike modern banjo/mandolin combos, they were quite capable of finding the heavy metal underneath your hood, and they do so a little later. The rockinghood become a little warm, in fact.
I saw Led Zeppelin at Earls Court in 1975. I just thought I'd mention that. They were magnificent.