In Mozart’s Words provides multilingual access to an annotated version of the voluminous correspondence of Mozart and his family - approximately 1,400 letters - that will progressively be made available online on this website. The website offers i) a univocal database of all references to people, places and musical works contained in the letters, facilitating the systematic search of all cited occurrences, and ii) access to background materials such as reviews, newspapers, documents, objects, paintings, engravings, and books as a corollary to the historical-critical annotations.

The Mozart family letters are the most extensive and richly detailed correspondence of any composer of the eighteenth century or earlier and a fundamental source of information concerning daily life at the time and Mozart's own biography. Numerous details of his life - including details of the early tours and the composer's time in Vienna - are known only from the letters. By the same token, they also give information concerning his compositional activities, including otherwise unknown works. Even beyond illuminating the genesis, authenticity and chronology of his music, however, the letters also give evidence concerning its performance, including questions of ornamentation, scoring, tempo and the size of the orchestras he played with, in Salzburg and elsewhere.