We know from eighteenth-century sources on performance practice that tempo fluctuations in the shape of agogic rubato, contrametric rubato and sectional changes of tempo were used extensively by performers in the late eighteenth century. Tempo fluctuations based on the performance aesthetics of the late eighteenth-century, comprehensive knowledge of music, and "good taste" are recommended in famous treatises by: Carl Philipp Emanuel Bach, Leopold Mozart, Daniel Gottlob Turk, Johann Joachim Quantz, Friedrich Wilhelm Marpurg, and later Carl Czerny. Today, recordings and live performances of the keyboard music of Joseph Haydn and his contemporaries seldom display any use of this expressive device, and there seems to be a lack of knowledge or ...