Since the emergence of 12-tone equal temperament (12-TET) in early modern Europe, proponents of 12-TET have pointed to the guitar and other fretted instruments as evidence that equal temperament represents not only a theoretical compromise, but a practical necessity. Such theorists have suggested that fretted instruments must rely on 12-TET in order to diminish the dissonances of historical tuning systems and enable consonant playability in all major and minor keys. Thus, for centuries, the guitar and similarly fretted instruments have been considered to be inextricably linked to the theoretical structure of 12-TET. Although 12-TET has achieved hegemony in the modern era (at the expense of historical, alternative and global systems of tuning and temperament), there persists a niche subculture of guitarists who will not so simply acquiesce to this theoretical ubiquity.

This paper explores the many ways in which contemporary guitarists have sought to reject the predominance of 12-TET by way of organological modification. Based on interviews with instrument builders and “microtonal” guitarists, this study examines how, in their pursuit of intonational idiosyncrasy, such instrumentalists have repositioned the concept of “in tune-ness” as a value that is negotiated through community discourse, craft knowledge and performance practices. In foregrounding these interventions, this study emphasizes that “in tune-ness” is not simply an inherited epistemological framework, but, instead, is a socio-cultural construction that remains ever evolving.