When Cenk Erdoğan testifies, with a broad grin creasing his face, that this week’s International Guitar Night concert is going to be “a two-hour freak show”, he doesn’t mean that it’s going to be the kind of thing Deadheads will want to throng to. Nor does he mean that he and his fellow guitarists Luca Stricagnoli, Antoine Boyer, and Samuel “Samuelito” Rouesnel are going to blast off into space with bolts of shoegaze distortion or postmodern digital trickery. Apart from Erdoğan himself, who’s bringing both an acoustic and an electric guitar on the road, the performers are going to be largely unplugged. But the talent assembled on the Massey Theatre stage is going to be freakish indeed.

Stricagnoli, who’ll host, is a social-media sensation for his otherworldly renditions of Gorillaz, Guns ’N Roses, and Iron Maiden hits, played on a one-of-a-kind triple-neck instrument. Boyer is the 24-year-old heir to Gypsy-jazz innovator Django Reinhardt, and an extremely skilled interpreter of the classical repertoire. Samuelito is a lightning-fast flamenco virtuoso. And Erdoğan has a sound—and an instrument—all his own. Combining contemporary jazz sonorities, a deep understanding of traditional Turkish music, and a love of South Asian ragas, he performs on fretless guitar, which gives him expressive possibilities more conventional performers can only dream of.

Ironically, though, he only began to discover his own voice after failing to emulate one of Samuelito’s primary mentors, the Spanish avant-flamenco musician Paco de Lucia.

“After I watched Paco de Lucia live, I thought that I wanted to play his music, the flamenco thing,” Erdoğan explains in a Skype interview from his Istanbul home. “But of course I didn’t have any YouTube or Internet in those days, 23 years ago, so I couldn’t make it work. I couldn’t understand the techniques and the movement of the hands, so I came to a point where I had to switch my way of guitar playing. I had to find something which I could make, because flamenco was so hard for me to understand. And at that time I came up with the fretless guitar, because of [pioneering Turkish guitarist] Erkan Oğur. So then I took out my frets and I started my experiments.”

Today, Erdoğan’s playing on nylon-string fretless incorporates many flamenco techniques, and is marked by his flawless articulation of complex chords—not an easy thing to do without frets to keep you in tune. On electric, he’s developed a unique fusion style, and sometimes uses an eBow electronic sustainer to make his instrument sound uncannily like a wind instrument. In Turkish music, there are nine different microtones between each whole tone, he explains. “Using that you can switch between all types of ethnic music, from Indian to Taiwanese or African microtonal stuff,” he adds. “It’s a really, really different world!”

It’s also a world Erdoğan is eager to share with North American audiences—and his fellow guitarists. It’s unclear whether his International Guitar Night colleagues will make their fretless debuts on this tour, but they’re already having fun with Erdoğan’s instruments backstage—except Stricagnoli, who might already have enough on his mind with his triple-neck acrobatics.

“Luca just said, ‘This is so sick that I don’t want to try it,’” Erdoğan reports, laughing. “But especially Samuelito loves it. Flamenco is also microtones in the singing, so it just makes sense.”