Isn't your question actually something like "how do you deal with an irascible person who fakes appreciation towards my skills while undermining the value such skills have on my community"? Maybe you find out things about him that fill you with real understanding. Most of the time, I'll say nothing and give them back a fake smile. Is there something specific that you've noticed has improved? In the grand scope of things, he only wastes a few seconds of your day.
I know you are new to Stack Exchange.
Is there something specific that you've noticed has improved? I would take the opportunity with someone who shows an interest to find out their interest in music and what they like about it. Sometimes people just want you to say "good morning" and it's perfectly fine to do so. Either he stops complimenting you or the music program gets a well-regarded if slightly embittered supporter within the parish. Perhaps instead of replying mindlessly, reply mindfully? No, I don't tell them off that "hey, you're being fake.