"Yes, I've heard it before, but I didn't know the name," Percy said in reply to the Clair de Lune song. He then blushed a little out of embarrassment. "And I.. didn't realized that Mozart wrote that song." To be honest, he also didn't know enough about Mozart and Beethoven to comment on Fleur's observation. He had thought himself familiar with Classical music, but in a matter of minutes, he'd exposed himself as being quite ignorant, and that made him uncomfortable.
He picked up his teacup to give his hands something to do, and tried to reclaim some of his esteem with Fleur's complement that he was more refined than the other Weasleys - this was an opinion he held of himself for quite some time, and it was nice to hear it being reinforced. Very nice, indeed.
"Ah! You see, I wanted to take lessons when I was young, but our family could never afford them, much less an instrument. So, when I moved out on my own and made a little bit of money, I purchased a keyboard and taught myself." This was a point of pride, and Percy held his head up. "My other siblings were more interested in Quidditch or in Charlie's case, dragons, and the twins, their jokes. I like to think I blossomed, after I left home." Never mind the fact he'd left the Burrow under unfortunate circumstances, after a family argument. "I wanted to familiarize myself with the arts, including music and theatre. Although... I'm afraid Classical music isn't my main focus. While I know a few pieces, I'm more fond of classic jazz. It's a bit of a shame that the village doesn't have much of an artistic community. Yes, there was a production of Peter Pan a few months ago, but it wasn't very polished, if you know what I mean, and it wasn't exactly Shakespeare, either."
If Percy sounded elitist, he wasn't trying, but somebody could certainly interpret that way.