Cipher presents visitors with a board with an 8 x 8 grid of holes into which decorative marbles provided can be placed. Setting a marble in a hole initiates a sound idea that will continue for several minutes, gradually decaying, unless the marble is first removed. Setting another marble into another hole on the same vertical or horizontal axis as the first will, as well as triggering a new sound idea associated with that hole, cause some form of sonic transformation upon the first sound idea (if it is still active). The transformation could be a change in tempo or speed, modulation of pitch, a spectral filter, rhythmic reconfiguration, or something else specific to the nature of the original sound. Considering the structure of holes in the interface, any sound idea begun can experience a total of 14 (7 vertical and 7 horizontal) different transformations and in any combination. Bearing in mind that there are 64 basic sound ideas, sonic outcomes based upon placement of the marbles is enormous. Visitors will, as well as enjoying the sonic experience of the piece, hopefully spend some time trying to decode and understand at least some of the mechanisms of the piece. The design of the piece suggests a puzzle or strategy game and in some ways the piece is both a puzzle and a game but there is no solution (or perhaps it could be considered that there are many solutions) and there is no winner. Strategy is advanced only through listening, the visual and physical side of the piece serves only as an impression of the current musical state of the piece.