Wagner? My favorite composition by him is Tristan und Isolde...I think. There are a couple in mind, but this one sticks out in my mind because that was one of the first operas I was exposed to as a teen that blew me away. As a person, Wagner was alot of things...not just a racist. One of my favorite composers of all time is Brahms. Wagner turned his nose up on Brahms, and so I have issues with Wagner on that principle alone. LOL! If it didn't act, behave, or smell like Wagner, Wagner felt or "pretended" it was inferior.
Hitler, however, was a manipulator. He used Wagner as a tool to manipulate the masses with no backbone to stand up against him. The fact that people believe Wagner was the reason Hitler was a racists is hilarious to me, because Hitler already had his views set that way WITHOUT Wagner's help. He used Wagner to boost his support, and people were dumb enough to fall for it in his country. Hitler was an jack@#$ and didn't need Wagner's help to guide his views. Its kind of like someone using a Celebrity to gather support behind a cause. Its sad he used Wagner's name this way, because although Wagner was a jerk at times, he never spreaded a message to kill Jewish people. He, in my opinion, was in fear of Jewish people having a handle on things in his country. He didn't want them as a whole "taking over". His was more of an insecurity instead of pure hate. Mendelssohn was pretty screwed over because of Wagner, but his music was still admired. I think there might have been a little jealousy coming from Wagner from that angle. Mendelssohn was a talented composer. Maybe Wagner was just upset because he was a scruffy looking something, LOL! Who knows.
I think people read more into Wagner than what it is. It's no excuse for his silly behavior, but he in no way was the same monster as Hitler. Even Wagner would turn over in his grave if he knew Hitler used his music as a backdrop to kill human beings. I just think Wagner was sort of a jerk in general. Schubert of that time was getting flack by Wagner and others too...not because his music wasn't wonderful. But it was looked at as "feminine" becuase people thought he was homosexual (I am sure he was). However, he was picked on like Mendelssohn was because of his sexual preference.
Like someone else stated, composers had issues too. I still defend Beethoven's behavior, although he was nutty. But I would be nutty too if I came from his background everyone wanted something from him. Mozart was a "pimp" (lol) and was obsessed by women. Lully indeed was a child molester of boys as del_ said, so some of the most famous composers are the most conflicted ones.
But they are human. They're flawed and looked under a microscope. I think Wagner made bad choices in life, but God gave him that gift to be responsible with it. It is up to us to be responsible with our gifts, because if we aren't people will use us an excuse to be ugly to others. That's how dumb the masses can be. One person with a small opinion or action can be used as an excuse for everyone else to think ignorant. Look at how one celeb move can cause a bunch of people to act or be stupid. I am so glad Hanna Montana didn't come out like Britney did in the 90's. I would have to look at 10 year olds wearing hoochie shirts and push up bras again while their parents blindly walk around with them like its ok. ROTFL! Is it completely the celeb's fault, no. But we have to be responsible. Even I as a parent and a performer have to be careful how I carry myself in public. I represent so much to people, even if I am not famous, when I get on the stage or walk into a PTA meeting. You'll be surprised how one person could cause others to think one way or another.