Two New Sound Discs For The Optigan, Glitchdelica & Guitarscape has introduced two new sound discs for the vintage Optigan, Glitchdelica & Guitarscape. Glitchdelica is an experimental rhythmic pattern generator. Forgoing the usual drums/chords/keys convention entirely, each button and key features a different loop, drawn from’s Pea Hicks’ archive of oddball instruments, electronics, and other sound sources.