1. The story --- about love, lust and state-imposed violence in Rome, circa 1800 -- will stun you, and maybe make you weep, even if you've seen the opera 20 times.
2. In the famous Act II aria "Vissi d'arte," the diva Floria Tosca cries, "I lived for art, I lived for love." Yet she faces nothing but violence and doom, and can make no sense of it.
3. The painter Mario Cavaradossi (Tosca's lover, hunted by the villainous Roman police) is given some big arias by Puccini (including Act I's "Recondita armonia") and long, rapturous love duets.
4. The opera features a freedom fighter, too: Cesare Angelotti, a friend of Cavaradossi's. You will meet him early on in "Tosca."
5. Scarpia, the chief of police, is the ultimate bad guy, worthy of a Coppola movie epic.