Irish bouzouki when having a longer scale length. The fifth course is usually either a lowest bass course tuned to C2 or D2 on an instrument with a long scale, or a highest treble course tuned to G4 or A4 on a shorter scale. Luthier Stefan Sobell, who coined the term "cittern" for his modern, mandolin-based instruments, originally used the term for short scale instruments irrespective of the number of their strings, but he now applies "cittern" to all 5 course instruments irrespective of scale length, and "octave mandolin" to all 4 course instruments, leaving out bouzouki entirely. Mandolin-family luthiers producing an
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"