Luna azul.

Real Blue Moon, with fake water.
Takes me right back to a performance by some fun guys I saw at the long-gone Liverpool Stadium in my student days. The skinny bass man spat into the audience then as well.
I'd like to point out that it was the 70s not the 50s! Sha Na Na were a highly talented group of musicians celebrating (and affectionately sending up) the music of two decades earlier. They appeared at Woodstock amazingly just before Hendrix, and such was their impact that they spawned a 50s revival, as seen in the film Grease (in which they performed) and the popular series Happy Days. I was something of a hippie as a student, and was struck by Bowzer's opening announcement: "I've got just one thing to say to you f**king hippies - rock 'n' roll is here to stay!" I wasn't really into that before-my-time stuff before the concert, but I had a new appreciation for it by the end.