The road to the modern Gibson flat-top…
The road to the modern Gibson flat-top acoustic began in 1926 when the L-1’s arched top was replaced with a flat, braced top. Those first flat-tops featured the familiar small and round L-body shape, a carved back, a long and narrow ebony pyramid bridge, and a unique early version of H-pattern top bracing. A year later the guitars had flat backs and the first sunbursts were being rubbed on flat tops.
By 1928, Gibson flat top designs had evolved into the L-0 shown here. The long and narrow ebony pyramid bridge was replaced with a stout, multi-layered rosewood one with interesting architecture and a 7th pin (more about these 7th pins to come). The H-bracing evolved as well, becoming slightly lighter and more flexible, with angles tweaked to improve mid-range presence, volume, and overall sweetness. The first adjustable truss-rods show up in flat tops in early 1928, and necks become a bit more comfortably rounded, narrower at the nut and more highly radiused at that same time.
It’s an interesting transition, and one that continued through 1933 when the first truly modern 14 fret steel string models are shipped from Kalamazoo.