This chapter examines the context and significance of the screen appropriation of jazz with particular emphasis on big-screen, feature-film formats and the perceived typecasting effect that, across several historical time periods while at the same time serving to mis/re-define what is a notoriously elusive genre. A mode of rebellion and detachment that may well have had its historical origins in an inward, African-American defence against slavery, 'cool' by its nature is an ultra-relative concept. The complex way in which jazz has featured in mainstream Western cinema holds up a mirror, perhaps a distorting mirror, to Anglo-American cultural and sociopolitical development. It seems that jazz on-screen has become caught between a rock and a hard place, or perhaps that should be between Rock and a hard place. Its cultural weight is ideal for historical situations but severely limiting in other contexts.