1791: MOZART’S LAST YEAR<i> by H.C. Robbins Landon (Schirmer/Macmillan: $19.95)</i>

“1791” is at once a detective story, a cultural history of music in 1791, a sober, respectful evaluation of documents pertaining to the chronology of Mozart’s compositions, and a work of love. H. C. Robbins Landon, author of “Mozart and the Masons” and the five-volume “Haydn: Chronicle and Works,” clearly knows the chief actors of the period as well as its music (he was also responsible for the first complete edition of Haydn’s symphonies). In Mozart’s short 36th year, he composed church music (for example, the Kyrie K. 341), dance music (for elaborate masked court balls attended by between 1,500 and 1,800 people, we learn), several piano concerti, “The Magic Flute,” “La Clemenza di Tito” (his last opera, K. 621), the melancholic clarinet concerto and his Requiem--altogether an unbelievable achievement.

The documentation that went into writing this book is impressive and includes studies of the paper types used in Mozart’s scores, inventories of his possessions used as collateral for loans, wardrobe lists, medical records of Mozart’s various illnesses, letters and other archival materials. Out of all this comes a striking picture of the details of the composer’s life, while engravings from the period add a visual appeal. We learn of Mozart’s passion for billiards and his deep affection for Constanze, his wife. We get a description of his apartment (it was 145 meters square). Robbins Landon also offers an analysis of the shift from larger public concerts to private soirees, resulting from the drain on finances caused by the war with the Turkish Empire; this naturally affected Mozart’s commissions and the type of music required. We learn of the precarious situation of Masonic lodges in Austria in 1791. Mozart’s librettist for “The Magic Flute” was another Mason (as was Haydn), Schikaneder, a man of the theater famous for his “machine-comedies,” fairy tales and magic operas. Robbins Landon suggests that Mozart wrote “The Magic Flute” to save the Masons from extinction.

“1791” illuminates many mysteries and dispels many myths surrounding the events of Mozart’s final months. The author specifically takes up the recent misconceptions of Mozart’s rivalry with Salieri and his supposed death by poisoning as popularized by Peter Shaffer’s play, “Amadeus.” Contrary to the common image of Mozart in his last months--destitute, paranoid, despairing--this volume presents a less dim view. One of Mozart’s last three symphonies, which many think he never heard, was conducted by none other than Salieri in what Landon calls “probably the last time Mozart ever heard a huge orchestra.”