Bouzouki Asia Minor and the subsequent exchange of populations between Greece and Turkey when the ethnic Greeks fled to Greece. The early bouzoukia were mostly three-string ("trichordo"), with three courses (six strings in three pairs) and were tuned in different ways, as to the scale one wanted to play. At the end of the 1950s, four-course (tetrachordo) bouzoukia started to gain popularity. The four-course bouzouki was made popular by Manolis Chiotis, who also used a tuning akin to standard guitar tuning, which made it easier for guitarists to play bouzouki, even as it angered purists. However it allowed for greater virtuosity
Irish bouzouki was introduced into Irish traditional music in the mid-1960s by Johnny Moynihan of the popular folk group Sweeney's Men. During the recording of their 1968 eponymous album, "Sweeney's Men", Andy Irvine also played Moynihan's bouzouki on the track "Johnston". Shortly after he returned from Eastern Europe in late 1969, Irvine met Dónal Lunny – who had been playing guitar up to that point – and gave him a Greek bouzouki he had brought back from his travels. Being left-handed, Lunny reversed the strings and critically, replaced the octave strings with unison strings, thus fundamentally changing the character of the instrument.