In 1993, the City of Rome launched an international invitations competition (9 participants) for the creation of a multifunctional complex designed to host musical and cultural events. The Renzo Piano Building Workshop project introduces a novelty to the call for tenders: do not group the three rooms in one building, but make three independent buildings. The three rooms are arranged symmetrically around an empty space. There is a fourth room, Cavea, an open-air amphitheater for performances and concerts, where about 3,000 spectators can be found. The three halls are conceived as real musical instruments. There are three large «harmonic boxes», with different capacities and features, structurally separated to enhance acoustic insulation.