Download: Led Zeppelin In Dallas, 1973 (Soundboard Recording)
Speaking of concerts in Dallas in the '70s, I just stumbled upon this live soundboard recording of a Led Zeppelin's May 18, 1973 performance at the Memorial Auditorium--but you'll need to be a bit torrent downloader to get it.
I know nothing about this show, other than that John Paul Jones apparently played the gig with two broken ribs. And, hell, that's badass enough for me. --Pete Freedman