Even more so than usual, this week's installment of Mandatory Music is brought to you by the letter M. From the first new arena rocker from Muse's just-announced Drones to our introduction to the newly plugged-in Mumford and Sons, we've got five tracks that'll make you say, "Mmm." And to make up for that loose C+C Music Factory reference, we'll even throw in a new track from St. Vincent that debuted on a recent episode of Girls. Everybody dance now.