Much non-Western music is microtonal, simply because it employs tuning systems different from the Western 12-tone system. For this reason, the Huygens-Fokker Foundation occasionally dedicates attention to “world music” in the Fokker organ series.
Following successful Fokker organ concerts featuring the Chinese erhu (Chinese violin), Indonesian gamelan, and Japanese shakuhachi flute, the spotlight now turns to Turkish music. For this special occasion, we invite the Istanbul-based Turkish classical guitarist, arranger, and designer of “adjustable” microtonal guitars, Tolgahan Çoğulu (1978, Ankara), to perform together with our unique 31-tone organ. The virtuosic Çoğulu has made it his life’s mission to render traditional Turkish music—which contains, among other influences, Arabic and Greek elements—on a Western instrument without losing its authenticity. To achieve this, in 2008 he designed a classical guitar with fully movable frets. Since then, he has been building a unique repertoire by arranging Anatolian folk music and traditional Ottoman makam music for his self-designed microtonal guitars. He also commissions established and emerging composers worldwide to create new works for him in various microtonal tunings; currently, more than forty composers are involved.
This morning, Çoğulu and Fokker organist Ere Lievonen face the challenging task of presenting various facets of Turkish music. Traditional Turkish music is monophonic and essentially melodic. It does not employ counterpoint or the extended harmonies developed in the West. Instead, emphasis is placed on playing with irregular rhythms (for example, in cycles of five or seven beats) and using dozens of different scales, each carrying its own expressive character. The programme includes traditional Turkish pieces as well as new works for guitar and Fokker organ by composers such as Ardashes Agoshian and Cengiz Arslanpay. The concert concludes with an improvisation (taksim), in which both musicians consecutively showcase their skills, with Çoğulu performing in the 31-tone system using his adjustable frets.

The Yunus Emre Institute (Turkish: Yunus Emre Enstitüsü) is Turkey’s cultural institute. Founded in 2009, it now has 64 centres in 53 countries worldwide. Through cultural diplomacy, the Institute seeks to raise awareness of Turkish culture, support the learning of the Turkish language, and promote greater exchange in the fields of art, culture, science, and education. 
