Mozart's demand on musical theatre could not be clearer: the sentence has often been quoted, but its consistency has hardly ever been heeded. It states that Mozart's operas are not drama with music, but drama through music. The libretto only determines the outer course of the work; the driving force lies in the notes. If this is so, there must be much more in the score than the realization of feelings. It must be possible to read from the music how the characters move, how they meet, what they feel, and whether they are telling the truth or lying. For this, however, the composer needs a 'sounding vocabulary.' If one is able to decipher it, a differentiated sound speech opens up to the listener, which is not limited to the operatic work. The gallop of a runaway horse is not only a sound metaphor for the awakened passion of Cherubino in 'Figaro,' but also the driving force in the first movement of the G minor Symphony. The metaphor of flapping wings is found in the depiction of love's expectation ('Figaro'), flightiness ('Così fan tutte'), and transformation in death ('Requiem'). This book interprets 'Le nozze di Figaro' from this perspective. It shows that through Mozart's music we hear not only the singing of the character, but also his mental state, posture, and movement. Already in the first number, one notices with amazement how Mozart's music determines the course of the conversation, how the couple Susanna and Figaro argue, although there is not a word about it in the libretto. Even the lighting on the stage and how the curtain is to open are captured in the sounds. If one follows the course of the opera in this way, one discovers behind the 'opera buffa,' as Mozart calls it in the 'Verzeichnüss aller meiner Werke,' more than a comedy: a sounding world theatre of Eros.