Landon, the leading Haydn scholar and a Mozart authority as well, here scrutinizes each month and each creative feat of the composer's final year--reassessing the old myths, reporting all the recent developments in Mozart scholarship, and offering a few theories of his own. Mozart and his wife Constanze were not reckless about money, Landon contends; furthermore, the composer's income in 1791 was substantial--and included, contrary to myth, 200 ducats for The Magic Flute. (They were in dire straits at the time of Mozart's death, Landon suggests, because of paying off old debts.) In minute, not-always-fascinating detail, Landon reconstructs the chronologies that led to the composition of the Requiem (some of the old myths are true) and Clemenza di Tito--drawing on Alan Tyson's study of Mozart's manuscript papers and watermarks. The Magic Flute is emphatically characterized as ""the first Masonic opera""--with analysis of the Masonic numerology, symbols, and rites throughout the opera. (Mozart and his librettist, Landon argues, were loyal Masons who broke the lodge's vow of silence in a doomed, last-ditch effort to fend off rising anti-Mason sentiment in Austria.) In reaction to Peter Shaffer's Amadeus and Wolfgang Hildesheimer's recent Mozart biography, Landon is especially vehement in two areas. Mozart was not poisoned by Salieri (who was indeed an envious rival); nor was his death connected to the violent domestic tragedy involving his pupil Magdalena Hofdemel. (Landon summarizes P.J. Davies' medical study of Mozart's many illnesses--and notes the ""devastatingly bad weather"" in the autumn of 1791.) And, according to Landon, Constanze has been unfairly maligned by Shaffer, Hildesheimer, and others: the evidence indicates that she was cultivated, loyal, and a spirited proponent of Mozart's work after the composer's untimely death at 35. More a dry and disjointed series of mini-essays than an involving narrative--but a balanced, lucid resource for serious students and passionate Mozart buffs.