High Zero is an annual festival, beginning in 1999, of Experimental Free Improvised Music in Baltimore, Maryland, United States.
It is hosted by the Red Room Collective, a volunteer group that sponsors weekly concerts in improvised music and experimental theater, film, poetry, etc.
High Zero draws from a large, international base of improvisors of many backgrounds, but traditionally gives half of the invitations for performance to Baltimore-based musicians.
Typical events include a musical bike ride, an invented instrument band, a parade through Fells Point, and other outdoor performances.
The festival has yielded six CDs on the Recorded label, each based around a particular performer (in order of release: Carol Genetti, Joe McPhee, Katt Hernandez, Jack Wright, Oleyumi Thomas and Neil Feather), which have, as a result of the festival's format, yielded documents of scarcely documented performers, including John Berndt, Paul Hoskins, John Dierker, Jason Willett, Chet Pancake, James Coleman, Sean Meehan, Michael Johnsen, Jerry Lim, Ian Nagoski, Dan Breen, Dave Gross, Andy Hayleck, Helena Espvall, Evan Rapport, Keenan Lawler, Christopher Meeder, and Jim Baker.