Glenn Gould was a fascinating pianist and a master at performing Bach. If you haven’t heard of him or listened to him play, read through this article. The video is proof that rules were made to be broken as Gould defies most rules of how to sit at a piano. There are very good reasons why one should sit with a straight back and relaxed arms – this prevents injury and allows good control over the keyboard – so Gould’s position probably shouldn’t be copied, but it does go to show all that you can accomplish despite how others think you should do something.