Mozart's enduring popularity, among music lovers as a composer and among music historians as a subject for continued study, lies at the heart of this book: even now, 250 years after his birth, Mozart remains an iconic figure in western society. One fortunate result of this – fortunate for both the music lover and the musicologist – is that new ‘facts’ about his life, new sources for his music, and new interpretations of his works are a regular feature of Mozart performance and the Mozart literature. As much as for any other composer, then, we constantly renew our relationship with Mozart, through listening and reading and thinking.

There have been some distinguished Mozart compendia in the past: H. C. Robbins Landon and Donald Mitchell's Mozart Companion of 1956 springs immediately to mind; so too does Landon's Mozart Compendium of 1990. The first of these coincided with the two hundredth anniversary of Mozart's birth, the second with the two hundredth anniversary of his death. The Cambridge Mozart Encyclopedia celebrates Mozart's two hundred and fiftieth birthday but it differs from those two volumes in significant ways. The Mozart Companion was a collection of extended, often brilliant, essays, organized by genre; it was not the volume's intention to give an account of Mozart's life or the contexts in which he worked. The Mozart Compendium, on the other hand, paid much more attention to Mozart's life and times but included much shorter essays on the music itself.