My most memorable concert was by Spirit, in about 1969 or 70. Ed Cassidy, "Mr. Skin", was the kickingest drummer I've seen before or since. He was about 47 then, and he still plays some. JJ Cale opened for them.
[youtube]
http://www.youtube.com/watch?v=RZfoMpnZ02c[/youtube]
They did four encores, the whole concert was about 5 hours.
Close after was Bonnie Raitt, in 1985, who said "I have a special guest for you tonight", and brought out the 90 year old Elizabeth "Libba" Cotton, who crawled onto a stool and unleashed a crackly but still true voice, accompanying herself on an acoustic guitar that she played left handed, but strung for right. She was the author of "Freight Train" and "You Are My Sunshine". The hit of the evening was when she told a story about a neighbor who used to complain to her mom about Libba playing and singing on the front porch. She said that she wrote a song about her, but could never play it around her mother or neighbor. "But now they both dead, and I can sing it all I want":
One old woman in this town
telling lies on me
Wish that woman up and die
telling lies on me....
Both concerts were at what was then "The Mosque" in Richmond, an operatic quality music hall. Because of the rampant political correctness of this age, it's now "The Landmark Theatre".