On Bach's Rhythm and Tempo Ido Abravaya Unlike works on tempo focusing on establishing the "correct" tempo of performing Bach's music, this work does not pretend to find the "right" tempo, nor does its author believe that Bach's tempi should - or could - be prescribed. Its aim is rather to gain, from the angle of tempo, a perspective on the much broader field of rhythm and rhythmic texture. Various questions on Bach's tempo are addressed here: Does tempo, as a variable parameter, conform to any laws; can we formulate a general theory on its behavior, i.e., range and modes of change? Were standard tempo units still accepted in the Baroque era? Does the tempo of a given piece directly derive form other parameters, like its formal, rhythmic and metric structure, or distribution of note values? One strategy of investigation offered here is that of Durational strata - viewing a composition through a cross section of its various note durations. Clear durational division, characteristic of late Renaissance and Baroque styles, has important repercussions on tempo. Other tempo determining factors, such as time signatures and tempo words in the music of J.S. Bach, are thoroughly surveyed, and examined in light of tempo theories of his time, as well as some present-day tempo philosophies.