DAddario Phosphor bronze acoustic guitar strings are known worldwide for their great, long-lasting sound. First used in 1974 by D Addario for making strings, Phosphor Bronze is synonymous with a warm acoustic tone. D Addario strings are produced by Sheryl Crow, Dixie Chicks, ED Gerhard, Richard Gilewitz, David Gray, Ben Harper, John Hiatt, Dave Matthews, John Mayer and Monte Montgomery. Gauges: .012 .016 .024 .032 .042 .053