A short piano piece was prepared by undergraduate and graduate piano students (N = 15) without guidance from their piano teachers. Temporal parameters were analyzed in several time frames, from a phrase-to-phrase level to an interonset interval. At a macro level, local tempo was shown to be a crucial parameter that divided the students into two groups that differed in their approach to a particular phrase, revealing the degree of proficiency in terms of interpretive decisions. The mathematical modeling of this phrase was further analyzed in terms of the mean squared error in comparison to the nominal (technical, strict tempo) and pianist (artistic) performance. This approach was employed to classify the students' performance in categories that were shown to be more related to their proficiency level than to their academic level. From the instrument pedagogy point of view, this research suggests fomenting in students a critical conscious about rhythm structure and its implications for coherence within the limits set by stylistic conventions of western classical music.