The Viennese aristocrat who reshaped Mozart's late style. In 1782, van Swieten introduced Mozart to Bach and Handel, fundamentally redirecting his late compositional style. The contrapuntal depth of the Jupiter Symphony, the late string quintets, and the Requiem all bear van Swieten's fingerprints.

Danish diplomat who married Constanze Mozart in 1809. He compiled the first comprehensive Mozart biography, published posthumously in 1828. Buried at Sebastiansfriedhof, the same cemetery that holds Leopold Mozart's grave. Without his patient documentary work and Constanze's cooperation, much of what is known about Mozart's private life would have been lost.