Carl Czerny,
Letters to a Young Lady
(1839)
“ Others endeavour to manifest their feelings by widely jerking out their elbows; or they mark the commencement of every bar by making a low bow with their head and chest, as if they were desirous of shewing reverence to their own playing. Others, after every short note, suddenly take up their hands as far from the keys as if they had touched a red hot iron. Many, while playing, put on a fierce and crabbed countenance ”
