Irish bouzouki Dónal Lunny, who replaced the octave strings on the two lower G and D courses with unison strings, thus reinforcing their lower frequencies. Soon after, on a visit with Irvine to the workshop of luthier Peter Abnett, Lunny commissioned a bouzouki to the specifications of a classic, 4-course Greek bouzouki but with unison strings and a three-piece, partially staved back. Since then, the instrument has been adapted for Irish traditional and other styles of folk music. The original Greek bouzouki was a three course/six-string instrument ("trichordo"). In the 1950s, a four course/eight-string ("tetrachordo") version was developed. The newer "tetrachordo" bouzouki
Bouzouki the mainstay of most Rebetiko music. It has fixed frets and 6 strings in three pairs. In the lower-pitched (bass) course, the pair consists of a thick wound string and a thin string, tuned an octave apart. The conventional modern tuning of the "trichordo" bouzouki is DD–AA–DD. This tuning was called the "European tuning" by Markos Vamvakaris, who mentioned (but failed to describe) several other tunings, or "douzenia", in his autobiography. The illustrated bouzouki was made by Karolos Tsakirian of Athens, and is a replica of a "trichordo" bouzouki made by his grandfather for Markos Vamvakaris. The absence of the