The Grammy Awards themselves may be kind of a joke at this point, but at least the ceremony’s organizers seem to understand what fans want: An all-star concert. CBS has announced that Jay-Z (who’s Magna Carta Holy Grail received several nominations, despite the fact that even he conceded it was a mediocre album) and Beyonce will join an impressive list of artists set to perform during Sunday night’s broadcast. The husband and wife duo, who will be taking the stage together, are now part of the line-up that also includes Lorde, Imagine Dragons, Willie Nelson, Daft Punk, Kendrick Lamar and a handful of others, during what has essentially become a one night, primetime mini-music festival …