Phosphor Bronze Acoustic Guitar Strings wound on Hexagonal Cores. The RARE phosphor bronze acoustic strings are a departure from the standard, good quality bronze string currently available...not necessarily better, but possessing a new, different and stronger "voice". When DR set out to produce a string with new characteristics, our goal was to redesign contemporary thinking about what phosphor bronze can do for a good acoustic guitar. Hand-carved arch-tops, dreadnaughts and good steel string acoustic guitars made of rosewood, maple, and mahogany seem to benefit from a distinct improvement in tone, depth, and sustain with RARE phosphor strings. Players who want a fatter and louder sound, as well as a deeper bottom (who like to hear their guitars ring out) will appreciate the RARE phosphor tone, sound, and feel. According to our heavy-playing bluegrass friend, three time National Flatpicking Guitar champion Steve Kaufman, RAREs last an unusually long time. Steve recommends DR to all his students.