Led Zeppelin ripped through an hour-plus set at the Texas International Pop Festival on August 31, 1969. Their set came on the second day of the three-day festival.
Janis Joplin performed on the first night of the festival, while Canned Heat and B.B. King played all three days. Grand Funk Railroad opened all three days as well.
Click here for audio of the entire Led Zeppelin set. The video footage is pretty incredible though, considering how rare footage of the band is from that era.