Pjw, only one; I was attending classes for the company I worked for in Chicago, (the classes were in Chicago) with other students from all over the country. That in itself was exciting. This was in 68, that's important.
As I recall, one of the guys I hooked up with was from "Bedford-Stuyvesant", another from Cleveland, and a third from Pittsburgh. We were all jazz fans, and heard Miles, Nina Simone, and Herbie Mann were all going to be on for one night at this auditorium.
We trusted Mr. New York to get the tickets, after all, he was the hippest. Was he a sight, in his sandals and Dashiki. (We wore suit and tie to class) The tickets as I remember were quite reasonable (that raised my suspicions). When we got to our seats, I have never been up so high inside of any building, I got airsick.
I think Miles was the first on. Now here is where I have to go to great length to put this into perspective; Miles was with tenor saxophonist Wayne Shorter, pianist Chick Corea on electric piano, drummer Tony Williams, and bassist Ron Carter. This is the kind of music they were playing. https://www.youtube.com/watch?v=H3Xjm-C1VS8
Miles came out on stage in a "Buckskin vest with long fringes"; I looked at Bed-Sty, who knew all things new and hip; he told me this was Miles new music, as well as new look. "I liked the old look and old music better", I responded.
The music and Miles new look was a complete shock to me.
Nina Simone and Herbie Mann were absolutely fantastic. There was a horrible storm raging outside, and many people who had seats didn't show, so we moved down 10 stories and sat in the good empty seats where we enjoyed Nina Simone who was followed by Herbie Mann.