On tuning of pianos I'm advocating systems which happen to be historic that use numbers of exact pure 3:2 fifths. This puts many notes of the scale exactly on the harmonics of lower strings, with numbers of near pure thirds or sweeter thirds than we're conventionally used to, and enables the instrument to give a stillness to the sound, and the music thereby, in contrast to the conventional tuning, as well as tonal colour differences between keys, which is what classical composers wrote for . . . as well as actually improving the sound of the instrument, making it less metallic, sweeter and more harmonious.