La Clemenza di Tito was Mozart's last Opera. In the aria 'Parto, parto' Sesto replies to Vitellia who has blamed him for not carrying out a conspiracy against the Emperor Tito. He agrees to go as she asks, but protests his love for her and promises to avenge her. In this aria there is also an obbligato part for the Basset Clarinet wich, in this arrangement, has to be played by the Solo Bb Clarinet.