Marmo (marble) and Onda (wave) symbolize two main features of the piece, namely the hardness and smoothness (marble) and the fluidity (waves). An ensemble of pianos is supposed to have a massive, solid block of sound, due to the impossibility of the instrument to produce sounds in a gradual way, as it happens with other instruments such as winds or strings. In this sense, I tried to enlarge the dynamic (and envelope) shape of this unusual ensemble, following the principle of aggregation, treating the sections of the piece as if they were different states of matter leading to each other, a transition’s game between solids and liquids. This formal principle starts right at the beginning, where single crystal drops slowly create a water wave.