This one-of-a-kind instrument was custom made by Korg in the mid-1980s at the request of Zawinul. It is not a synthesizer, as it has no capabilities to produce sound of its own. Rather, it is a MIDI controller consisting of a melodica mouthpiece for breath control, and a set of accordion-like buttons. A picture of Zawinul playing the Pepe appears in the April 1988 issue of downbeat. In the accompanying article, Zawinul says, “Originally, I was an accordion player and it was always my dream to have an instrument like the accordion. It looks like a bassoon mouthpiece, but I used a mouthpiece from a Melodica. On the right hand side, it’s an accordion with buttons. It’s very difficult to learn the accordion with two notes on each button, but with Pepe’s six notes, it becomes a real head trip.”

Here's a video of Joe playing the "Pépe"