RIP, Mr. Yarrow. Enjoyed the music. From AP: LOS ANGELES (AP) — Peter Yarrow, the singer-songwriter best known as one-third of Peter, Paul and Mary, the folk-music trio whose impassioned harmonies transfixed millions as they lifted their voices in favor of civil rights and against war, has died. He was 86. Yarrow, who also co-wrote the group’s most enduring song, “Puff the Magic Dragon,” died Tuesday in New York, publicist Ken Sunshine said. Yarrow had bladder cancer for the past four years.