Showbiz411: Jay Z is taking on Spotify, Pandora and YouTube with his newly approved $56 million acquisition of Swedish streaming service Aspiro. The rap entrepreneur is said to have hosted a group of music superstars — Madonna, Kanye West, Nikki Minaj, Daft Punk, Beyoncé and others — to discuss how they could turn Aspiro into a streaming music and video service akin to the old United Artists pictures, in which artists would better profit from their work.