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
Irish bouzouki families are related and the bouzouki is a part of that. At any rate, since the genesis of the Irish bouzouki in the late 1960s, luthiers have incorporated so many aspects of mandolin construction, particularly when building archtop Irish bouzoukis, that for most it is a moot point. For many builders and players, the terms "bouzouki", "cittern", and "octave mandolin" are more or less synonymous. The name cittern is often applied to instruments of five courses (ten strings), especially those having a scale length between 20 and 22 inches (500mm and 550mm). They are also occasionally called "10 string bouzoukis"