Optical Slipknot Ceiling
The height above which the fans of a given band cease to publicly acknowledge their allegiance, i.e. the apparent maximum height of anyone habitually wearing their merchandised clothing. Approximately 1.6m for its namesake.
The Garcia (Gc): US Unit of Musical Self-Indulgence
Given an American Standard Audience, the fraction of listeners at a given point in time who would be grateful if the band dropped dead. The level of Garcias legally permitted in an open space has been a matter of debate amongst legislators and environmentalists since the Free Jazz Act of 1972.
The International Bureau of Weights and Measures has yet to agree on an SI unit that corresponds the Garcia for adoption by the EU. Environmental campaigners have complained that this bureaucratic holdup exacerbates the increasing problem caused by late Radiohead albums in built up areas.