"Yesterday--would you believe it?" wrote Nietzsche, "I heard Bizet's masterwork for the 20th time." So opens his book known as "The Case of Wagner; A Musician's Problem."
"Again, I attended with a gentle devotion; I did not run away, again. This victory over my impatience surprises me. How fulfilling is such a work! One turns into a masterpiece with it.--And, indeed, I appeared to myself, every time that I heard Carmen, to be more of a philosopher, a better philosopher than I usually appear to myself: having become so patient, so happy, so East-Indian, so sedentary... To sit for five hours: the first step to sanctity!--May I say that Bizet's orchestral sound is the only one I can still endure?"
The music of Wagner and Bizet's Carmen were both experiencing rapid upward trajectories in popularity in 1888 when Nietzsche's book was first published. But they were not equal choices for Nietzsche. He knew Wagner quite well as a young man, so this shift in his alliances is significant.
Some writers have observed the relationship between Wagner and Nietzsche as having elements of a father/son dynamic because Nietzsche's father died when he was young and would have been more-or-less Wagner's age had he lived, and Wagner had children late in life but could have had children who were Nietzsche's age. The falling out between the two had all the complexities of family.
The vast majority of Nietzsche's text is directed against the works of Wagner. Wagner sought perfection in the total synthesis of all art forms. It is therefore a powerful thrust when Nietzsche describes perfection in Carmen:
"This music appears perfect to me. It approaches lightly, flexibly, courteously. It is pleasant, it does not perspire. 'That which is good is light, everything divine walks on tender feet': the first premise of my aesthetic. This music is vicious, refined, fatalistic: with it, it stays popular--it has the refinement of a race, not that of an individual. It is rich. It is precise. It builds, it organizes, accomplishes its goal."
I believe that one can also frame Nietzsche's perspective toward Carmen as a quasi-familial reaction:
"To repeat it: I become a better man when Bizet speaks to me, also a better musician, a better listener. Can one even still listen better?--I even bury my ears beneath this music, I hear its origin. It appears to me that I am experiencing its creation--[...] Bizet makes me fertile. Everything good makes me fertile. I have no other gratitude,--I also have no other proof for that which is good."
It is as though Nietzsche was rescued by Carmen. He leaves his Wagnerian family to elope with an opera.
"Here, another sensuality speaks, another sensitivity, another serenity," wrote Nietzsche, "Finally love, love that is translated back into nature! [...] Can you already see how much this music improves me?"