Charlie Chan at the Opera is considered by many to be the best Warner Oland Charlie Chan film, probably due to the coacting of Boris Karloff. This is the 13th film starring Oland as Chan and produced by Fox in 1936.
Chan soon investigates the killings and despite the presence of Gravelle, there are other suspects who may be the real killer. They suspects, excluding Gravelle, include Lilli Rochelle, the opera companys prima donna who has been having a secret affair with Enrico Barelli, the baritone Mr. Whitely, Madame Rochelles husband who has warned Barelli to stay away from his wife Anita Barelli, the opera companys number two soprano who has learned of her husbands affair with Lilli Rochelle and Phil Childers, the fiancee of Lillis unacknowledged daughter who has been refused permission to marry the daughter.Clues found by Chan to apprehend the killer include a torn newspaper, a charred note, a heel mark on a newspaper picture, and a bloodstained belt. Among the questions asked are who has been threatening Lilli Rochelles life, the mystery man in Barellis dressing room before he is murdered, and why does Chan insist that the opera be formed twice in one evening? ........
Source: Wikipedia