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
Bouzouki the pair are tuned to the same note. In the two lower-pitched (bass) courses, the pair consists of a thick wound string and a thin string tuned an octave apart. On the bouzouki the lower-pitched string comes first in these courses, the reverse of most other instruments with octave-paired courses (such as the 12-string guitar, charango or bajo sexto). These 'octave strings' add to the fullness of the sound and are used in chords and bass drones (continuous low notes that are played throughout the music). The guitar-like tuning was introduced by composer and soloist Manolis Hiotis, who found it