I saw the Moody Blues live several times back in the 80's. Once at Tanglewood in Lenox, MA, an outdoor venue which is better known as the Boston Symphony Orchestra's summer residence. That was a wild night. I remember it well because they allowed you to bring your own alcohol as long as it wasn't in a bottle or can. Most people used wine skins but I bought a "beer ball" of Matt's Beer. which was a plastic little keg with a few gallons of beer. I got to the front of the ticket line and they said, "No bottles or cans". I said, "It's plastic". They shrugged and let me take it in.
I sold several cups of that shitty beer for $10 so I drank for free that night.
BTW - it was a great concert too.