Does tempo, as a variable parameter, conform to any laws; can any general theory on the "behaviour" of tempo, i.e., its range and modes of change, be formulated? Was the concept of a standardized, or normal tempo unit, still accepted in the Baroque era? Is the tempo of a given piece directly derived from other musical parameters, such as its formal, rhythmic and metric structure, distribution of note values and similar factors?
One strategy of rhythmic description is effected by what I term durational strata - viewing a composition, an entire genre or a style through a cross section, as it were, of its various note durationsThe clearest evidence that in certain styles different note values are differently treated is found in the so-called "Palestrina style", but a similar phenomenon can be observed also in Baroque styles, which necessarily has some repercussions on tempo. Other tempo-determining factors, such as time signatures and tempo words in the music of J. S. Bach are surveyed. These factors, read directly from the musical text, are compared against the most significant tempo theories of Bach's time, by Quantz and Kirnberger. The conclusions drawn from these data are used in the evaluation and critique of some present-day tempo philosophies. The aim of the present work is not to establish new prescriptions of the "right" tempo in Bach's music, but rather, from the angle of tempo, to gain a perspective on the much broader field of rhythm and rhythmic texture.