Originally Posted by Psy-Fi

August 6, 1967. I was 5 and with my parents in Montreal, Canada, attending Expo '67. We saw a free, outdoor, afternoon show featuring Jefferson Airplane (I was familiar with them, as they were getting a lot of radio airplay with "White Rabbit" and "Somebody to Love") and an opening act I hadn't heard of called "The Grateful Dead."

The first show I saw without adult supervision, was David Bowie at Boston Garden in Boston, MA on May 6, 1978.
As soon as I sat in my seat, the person sitting to my right handed me a lit joint and told me to take a toke and pass it on down the line. My buddy and me had people handing us lit joints left and right all through the show. There were so many people smoking weed, there was a marijuana haze throughout the arena. To this day (and many hundreds of shows later) it's the most pot smoking I've ever seen occur at a concert.
Some of the songs from the show, wound up being included on Bowie's "Stage" album, released later that year.
Recently, I found and downloaded a good quality audience recording of the entire show.

I've searched for a recording of the Grateful Dead/Jefferson Airplane show, but it appears there was no recording made of that performance, either by Owsley (the LSD chemist and soundman for The Grateful Dead, who recorded most of their performances while he was with the band) or any member of the audience.
I'm hoping a recording of that concert will surface someday.