This paper builds on writings in psychology and philosophy to offer an “ecological” description of jazz improvisation. The description is grounded in the analogy of navigation through a complex environment, an environment that comprises the harmonic and metrical scheme on which the improvisation is based coupled with broader stylistic norms. The improvising soloist perceives this environment in terms of its “affordances,” that is, the possibilities for action that it offers (Gibson, 1979). While navigating the improvisational environment, the soloist also seeks opportunities for artistic display—motivic development, conspicuous risk-taking, and so on. Errors in improvisation reflect the soloist’s misperception of the environment’s affordances. Learning to improvise is a matter of refining perception through repeated experiences of improvisational success and failure. To bring the description to life, I offer evidence from an exploratory study of improvisational errors. The ecological description leads to new interpretations of the referent (the conceptual frame for a solo), improvisational learning and memory, and temporal coordination between soloist and ensemble. It counterbalances the prevailing computational view of improvisation, oriented around input, processing, and output.