Did you know that Mozart had been a Freemason?
I must say right away that I'm not a specialist on Mozart:) I base my information on a Wiki article about one of his operas, Die Zauberfleute (The Magic Flute), which premiered in September 1791 in Vienna, a couple of months before the composer's death and was a great success.
According to Wikipedia, the opera has prominent Masonic elements and was heavily influenced by the Enlightenment philosophy. According to some researchers, the wicked Queen of the Night symbolises the Austrian Empress Maria Theresa, who was anti-Masonic.
The Queen of the Night deceives a young handsome prince called Tamino telling him that the evil king Sarastro abducted her daughter, instructs him to rescue her and gives him a magic flute. However, Sarastro is not at all evil, he is an enlightened sovereign who rules according to reason. Sarastro refuses to return the girl to her mother due to the latter's bad influence, but he informs Tamino that he can win the princess if he undergoes the trials which will make him enlightened, too.
In the end, the Queen of the Night and her servants are cast into the eternal night, the lovers come together, and after giving thanks to the heathen gods Isis an Osiris, everybody enters the new era of brotherhood (and presumably, equality and liberty:) And people nowadays complain about Harry Potter:)
Anyway, the music is amazingly beautiful. In the clip you can see the wicked queen inciting her daughter to murder Sarastro.
If you want to know more about the topic, click on the link above.