### Clue: Wagner opera in France's nothing unknown, I added (6)
### Answer: RIENZI 
 ### Explanation: Wagner opera in France's nothing unknown, I added (6)
**RIEN** ("in France, nothing") + **Z** ("unknown") with **I** *added*. 
*"Rienzi" is an early Richard Wagner opera, first performed in 1842 and considered his first "hit".