(150-200 words) The MIDI Toolbox is a compilation of functions for analyzing and visualizing MIDI files in the Matlab computing environment. In this article, the basic issues of the Toolbox are summarized and demonstrated with examples ranging from melodic contour, similarity, keyfinding, meter-finding to segmentation. The Toolbox is based on symbolic musical data but signal processing methods are applied to cover such aspects of musical behaviour as geometric representations and short-term memory. Besides simple manipulation and filtering functions, the toolbox contains cognitively inspired analytic techniques that are suitable for contextdependent musical analysis, a prerequisite for many music information retrieval applications.