MixMash is an interactive tool to assist users in the creation of music mashups based on cross-modal associations between musical content analysis and information visualisation. We propose a new interactive visualisation of multidimensional musical attributes—hierarchical harmonic compatibility, onset density, spectral region, and timbral similarity—extracted from a large collection of audio tracks. All tracks are represented as nodes whose distances and edge connections indicate their harmonic compatibility as a result of a force-directed graph. In addition, we provide a visual language that aims to enhance the tool usability and foster creative endeavour in the search for meaningful music mixes.