From an ecological point of view, listening to music is a complex experience in which both bottom-up and top-down processes work together making possible an understanding of a musical piece. Listeners build their musical perceptions out of the individual parametric features of the musical work, but also by calling into play their prior musical experience, i.e., their knowledge of a musical style. In this sense, it has been argued that all we know about a particular musical style influences what we perceive, that is, the way in which the mind organizes sensorial data presented to it. The aim of the present research was to investigate if listeners are influenced by their stylistic knowledge on the specific area of categorical rhythm perception. An experiment was run in which seventy-four participants were tested in their categorical perception and their stylistic knowledge asking them to perform an identification task and to complete a questionnaire about their stylistic knowledge, respectively. Nine rhythmic stimuli were used. Three of them were especially composed expressive versions where the inter-onset intervals didn’t correspond to integer-ratio relations. They belonged to different stylistic musical contexts (jazz -swing-, folcklore argentino -carnavalito- and medieval dance -trotto-). Results showed that subjects who possessed specific stylistic knowledge about the musical contexts in which expressive patterns were presented tended to categorize them in a different way that subjects who did not possessed that specific knowledge. They also showed that those rhythmic patterns that had proportional inter-onset intervals were categorized in a different way according to the stylistic context in which they were presented.