STRING / STRING SET FOR ACOUSTIC GUITAR String Sets Acoustic Guitar Series EJ Bronze 80/20 Light (012 - 016 - 024 - 032 - 042 - 053). The 80/20 Bronze, commonly known as Brass, is the original alloy of the strings for acoustics selected by John D'Addario Sr. and John D'Angelico in the 1930s. The 80/20 Brass strings are very popular for the recording due to its clear, deep and projection tone, and attractive to many traditionalists and vintage enthusiasts for its historical significance.