Definitely one of the best live performances I've ever seen was just Janis Ian and her guitar at the Regina Folk Festival a good number of years ago. There was still one act to go after her and I remember a number of people saying they pitied the group that had to follow that performance.
I also love Janis Ian.
I've more CD titles of hers, and seen her live more times, than any other artist.
The photo of Janis and me was taken at The Sage, Gateshead, when she was on tour with Tom Paxton in 2014.