Timbre has been conceived of as a multidimensional sensory attribute and as a carrier of perceptually useful information about the mechanics of the sound source. To date, research on musical timbre has focused on defining its acoustical correlates, whereas fragmentary evidence is available on the influence of mechanical parameters. We quantified the extent to which mechanical properties of the sound source are associated with structures in the data from published identification and dissimilarity-rating studies. We focus on two macroscopic mechanical properties: the musical instrument family and excitation type. Identification confusions are significantly more frequent for same-family instruments. With dissimilarity ratings, same-family or same-excitation tones are judged more similar and tend to occupy the same region of multidimensional-scaling spaces. As such, significant associations between the perception of musical timbre and the mechanics of the sound source emerge even when not explicitly demanded by the task.