I would like to ask a question about the speed of playing a piece on the piano. For example, I have listened to a special “Polonaise” in G-minor from the Maria Magdalena Notebook by Johann Sebastian Bach many years ago, and it was played on a violin very slowly, in fact, it was very touching and the violin was almost “weeping”. I then re-discovered the same Polonaise a few years ago on a CD called “Visions of Bach”. And here again it is played on the violin (Celtic Fiddle) very slowly, thoughtfully and very sensitively. I also heard it played on a piano and it was played rather fast. Does anyone know how to play these pieces, are there any rules or is it everyone’s own choice how to express themselves? I have also noticed Sonatas of D. Scarlatti often being played very quickly and only rarely does anyone play Scarlatti slowly enough to appreciate every single tone and "let it linger a little". Are there any rules how to play or is it everyone's own choice?