Irish bouzouki Johnny Moynihan (apparently in an attempt to replicate the open, droning sound of Appalachian "clawhammer" banjo) first on the mandolin and then transferred to a Greek bouzouki. It was later picked up by Andy Irvine and Dónal Lunny, and quickly became the next thing to a standard tuning for the 4 course instrument. Other tunings used, although by a minority of players, are "octave mandolin" tuning G2 D3 A3 E4, and "Open D" tuning A2 D3 A3 D4. "Open G" G2 D3 G3 D4, is used by some players and has proven useful for "bottleneck" slide playing. The GDAD tuning
Irish bouzouki and a flat back with straight sides replaced the round, stave-built back of the Greek bouzouki. English builder Peter Abnett, who was the first instrument-maker to build a uniquely "Irish" bouzouki – for Dónal Lunny in 1970 – developed a hybrid design with a 3-piece partially staved back and straight sides. All of the initial Irish bouzoukis had flat tops, but within a few years a few luthiers such as Stefan Sobell began experimenting with carved, arched tops, taking their cue from American archtop guitars and mandolins. Even so, today the overwhelming majority of builders continue to opt for flat