early development of the twin-sound hole guitar is partially attributed to the glw, with at least two of the twin-hole guitars becoming a signature style for keola and kapono beamer as their musical careers evolved, specifically around the traditional hawaiian slack-key guitar style. due to the immaturity of the twin-hole style early on, some twin-hole guitars were returned to the glw for repair, ostensibly due to distorted tops (sound board) as a result of insufficient bracing under the bridge.