Tom Morello, the Rage Against the Machine guitarist who is no stranger to activism, performed a song inspired by the death of Michael Brown last month and the subsequent protests in the 18-year-old’s community of Ferguson, Missouri. Performing as his solo alter ego Nightwatchman, Morello debuted “Walking on Ferguson” over the weekend at the Rock Out! for Jail Guitar Door benefit concert in Los Angeles. At one point, he broke out into a guitar solo — with his mouth. Morello has been vocal about the unrest in Ferguson, particularly on Twitter.