In the last decades, musical cognitive psychology has intervened to build a bridge towards the comprehension of musical structures. The present paper studies the behavior of several students and music professionals in relation to grouping structure and it does so through the performance analysis of the first movement of Hindemith's sonata for flute and piano, according to the rules formulated by Lerdahl and Jackendoff, movement chosen because of its tonal ambiguity. The participants of this experiment are three medium level female Conservatory students. They performed the aforementioned piece after studying it for a whole trimester. The performance of the same piece by three professional musicians was also analyzed, using the appropriate commercial recordings for this purpose. This analysis includes the choice of group limits used in performance by both professionals and students and the comparison of both groups' results. Differences were observed in the placement of said limits by the different groups but all of them respected the set of rules formulated by Lerdahl and Jackendoff.
