While current models of sound change distinguish between an innovation by an individual and its spread through the community (Lindblom 1990, Croft 2000, Stevens and Harrington 2014), I argue in this presentation that within a speech community the forces of imitation (Tomasello 2008), entrainment (Shockley et al. 2007), accommodation (Goldinger 1998, Harrington 2012), and cooperation between speaker and listener (Lerner 2002) make it possible for innovations to arise simultaneously across speakers, so that innovation and spread are not necessarily separate phenomena.