Why does the general demeanor of others change as soon as they begin to "talk shop" or do something else that puts them into "work-mode"? We propose that such phenomena reflect an instance of incidental priming in which environmental cues activate actional "sets" formed through extensive training in a particular domain (e.g., music). Accordingly, we demonstrated that, by activating a "musician set," incidental musically-related stimuli prime musicians to spend more time on a domain-irrelevant task rehearsing nonsense words as compared to controls or non-primed musicians, as this set should involve a tendency towards deliberative practice. This finding provides additional evidence for a central tenet of social cognition research--that the mere presence of ambient stimuli influences behavioral dispositions systematically, in ways that often escape one's awareness. (Contains 1 figure.)