Many innovations in the history of guitars relate to making the instrument louder. Substituting steel wire for gut strings made a big difference in the volume. However, the increased tension of steel strings didn’t just increase the volume but created a variety of problems which were not entirely addressed by guitar makers until my lifetime. Steel tension would pull off bridges. Thus many guitars at that time were fitted with stamped steep tailpieces and used a floating bridge. Another problem was the warping of the guitar neck due to increased tension. Eventually guitar makers reinforced the neck with ebony or steel.
A problem that still was common when I started to play guitar was the difficulty in finding light gauge steel strings. The Martin guitars of the 1930s are often described as the golden era. These guitars were still lightly braced for gut strings. Guitar makers began making more robust guitars to deal with the problems of the high tension of steel strings just as string manufacturers were improving their processes to provide lighter gauge strings. This misalignment of technology is why the 1950s are perhaps the dark ages of acoustic guitars. Today, everything is back in alignment. Indeed I believe we are in another golden age of guitar making.