YouTube copyright enforcement is bizarre. Claims against you seem unfounded if your playing classical works and if anyone could claim copyright of your performa

YouTube copyright enforcement is bizarre. Claims against you seem unfounded if your playing classical works and if anyone could claim copyright of your performance is you, as it's a new performance and arrangement makes that your copyright. I have used commercial tracks on videos I've posted and YouTube has authorised saying the copyright owner allows me too in exchange for me accepting adverts on my video. I know they don't check copyright much, as I once got locked out of an old YouTube account I had, forgot the password and didn't have access to the email I signed up with. But I wanted the only video on the channel taken down, so I did a copyright complaint against myself, YouTube accepted it!