Four people walk into a bar each carrying briefcases containing one million dollars worth of your favourite currency. None of them have ever heard Prog Rock before:
The first says to you: I'll give you my briefcase if you can name for me one artist that absolutely typifies Prog Rock.
The second says to you: I'll give you my briefcase if you can name for me one album that absolutely typifies Prog Rock.
The third says to you: I'll give you my briefcase if you can name for me one song that absolutely typifies Prog Rock.
The Fourth says to you: I'll give you my briefcase if you can name for me the first Prog Rock song ever.
What would you say to each person?
And what's the catch?
Edited by Arbiter