East-coast Guitarist/Composer Flynn Cohen leads a workshop on building simple versions of instruments that produce natural harmonics of vibrating strings and columns of air: South African-style Umqangi mouth bows and pvc overtone flutes. Attendees can choose to build either one or both. There will be instruction in the basic playing technique and a chance to jam with others. Workshop is free of charge, sponsored by a grant from the City of Oakland. All building materials and tools will be provided.