Tomorrow (tonight 12:01am) brings Jay Z’s “Magna Carta” album to 1 million Samsung app downloaders. (I sure hope the album comes in more easily than the app!) Anyway, as a great publicity stunt, Roc Nation-Def Jam has put the “Magna Carta” cover art on display in England at Salisbury Cathedral. That’s one of the four places where parts of the real “Magna Carta” are displayed. A desecration of history? No doubt. But a funny idea nonetheless.