Block Jam is a musical interface controlled by the arrangement of 25 tangible blocks. By arranging the blocks musical phrases and sequences are created, allowing multiple users to play and collaborate. The system takes advantage of both graphical and tangible user interfaces. Each block has a visual display and a combination of a gestural input and a click-able input. Each Block metaphorically contains a sound group that can be chosen via the gestural input, the click-able input changes a block functionally. Thus, musically complex and engaging configurations can be rapidly assembled. The tangible nature of the blocks and the intuitive interface promotes face-to-face collaboration, and the presence of the GUI allows for remote collaboration across a network.