Mozart's wife Konstanze (1762-1842) was the cousin of Karl Maria von Weber. Mozart wrote several vocal parts for the trained soprano, including the soprano part of the Great C Minor Mass. After his death, Konstanze managed his estate. The letters and documents, accompanied by a comprehensive biographical introduction from the editor Arthur Schurig (1870-1929), provide a good insight into the couple's married life as well as Konstanze's efforts regarding Mozart's work. This is a reprint of the work published in 1922.