I saw a similar thread at Tech Talk Forum, and enjoyed it. So I am shamelessly copying it here.
Concerts you wished you hadn’t gone to:
May 1970 – Grand Funk Rail Road – Chapel Hill, NC
It was the annual spring concert festival held every year where I went to college, called Jubilee Weekend. I was a senior (would soon graduate), and I went to see Grand Funk Railroad only so I could be early for what followed, Joe Cocker (see below). I’d never heard of GFRR before, so I went in open-minded. They were dreadful. The outdoor sound system was actually good (compared to what was the usual case), but the band itself sounded awful. They appeared to be well rehearsed, but their material was just bad. There were no other words for it other than their music sucked.
Everyone has seen concerts by well-known bands that disappointed. Usually the sound system or venue was miserable, or the band was too tired, too drunk, or too stoned to perform well. But GFRR were beyond explanation or excuse – they were that bad.
When I noticed how many younger undergrads around me seemed to think they were the most awesome band they had ever seen, I felt embarrassed to be there. I realized that the university was being taken over by youngsters (with no taste) and it was time for me to leave. And I began to wonder if I had witnessed that smoking dope might really cause brain damage.
Concerts you were glad you went to:
May 1970 – Joe Cocker & The Mad Dogs & Englishmen – Chapel Hill, NC
This was later the same day as the GFRR abomination. This show restored my faith in all that was good and wonderful about rock & roll. They were outstanding. As that band was only together for one short touring season, I was glad to have been able to see them.
Concerts you wished you had gone to
Mitch Ryder & the Detroit Wheels – a high school friend saw them in 1966 at a home coming dance at George Washington University! She said they were wonderful, and unlike the usual local cover bands at such dances, these guys captivated the crowd. Less than a year later, this band was broken up by some miserable excuse of a record producer/band manager. I wish I had seen them.
Concerts that surprised you because the band was much better than you expected, or bands you saw before they were well known
Led Zeppelin – It was the summer of 1969 at a large outdoor festival in Atlanta, GA that preceded Woodstock by a month or so. It wasn’t near New York, and there was no mud, movie, or album, so it wasn’t as well remembered. Led Zeppelin was already quite well known, but I expected them to be more of a studio band that didn’t do live performances well. I was surprised at how good they were live, especially Jimmy Page. There were plenty of other well known bands at that same show that put on highly forgettable performances.
Robert Palmer – He was completly unknown to me. It was 1976 and I was in Connecticut. I went to see a show at Wesleyan College in Middletown, CT. I forget who was supposed to play, but they had cancelled, and a British guy named Robert Palmer came out instead. He was dressed all in white, white top hat, coat with long tails, white gloves, walking stick, and white shoes. He was backed up by an excellent 10-piece band. He was phenomenal. I instantly became a Robert Palmer fan.
Any one else?