ML in lemmy.ml stands for Marxist Leninist, I am not joking. The creators and developers of lemmy.ml are pretty left leaning.
I develop acoustic echo cancellation algorithms for a living. if there is echo also when your mic is muted, that means that it is not really muted. This makes me think that probably your headphone is feeding back the headphones signal to the microphone, probably due to faulty circuits inside you headphones.
Check out imslp.org, you will find any classical music piano sheet, in multiple version and also with audio recordings
@FrullaPapaya
@lemmy.world