The African-rooted Candombe drumming is one of the most characteristic traits of Uruguayan culture. Yet its complex rhythm can sound difficult to decode for unfamiliar listeners. In this work the authors present tools for detailed analysis of the rhythmic patterns of each type of drum found in Candombe performances, using as a platform an assortment of recordings by different players, with annotated metrical structures. For a given recording, the first tool consists in constructing a map of bar-length patterns that enables the inspection of their evolution over time, the second tool clusters those patterns, and maps the result onto a low dimensional space for visualization. A set of controlled experiments illustrate and justify the fundamentals of the described strategies, which are then applied to the analysis of real piano drum performances as a case study. The tests demonstrate that the obtained clusters match characteristic patterns of the instrument, and also allows the disclosure of differences and similarities among schools or personal styles. The output of this investigation is an interactive software tool for the analysis of Candombe recordings oriented towards the study of the underlying structures and rules governing performance styles and improvisation