One of the voices of the Summer of Love has died. Scott McKenzie, known for “San Francisco (Be Sure to Wear Flowers in Your Hair),” passed away Saturday in Los Angeles, according to a statement on his website. He was 73. The artist suffered from Guillain-Barré syndrome, an autoimmune disease that afflicts the nervous system. “San Francisco” was written by the Mamas and the Papas leader John Phillips, and McKenzie toured with the group later in his career. He also had a hand in writing “Kokomo,” a hit for the Beach Boys.