Watch Movies2Watch. When he composed his motet ‘Exsultate jubilate’ K.165, Mozart was only 17 years old. He was then at the height of his fame. He was 35 when he wrote ‘The Magic Flute’ and died shortly afterwards. Dutch conductor Ton Koopman presents a programme that traces the stages of the composer's life. Russian soprano Julia Lezhneva performs the solo parts.