I know the concept of chord progression is not applicable in the period of the Baroque. However, I cannot help but hear certain progressions as I listen to Bach orchestral suites or concertos, or Vivaldi for that matter. They seems to rise or fall on the diatonic scale by a step, repeating the same motif. Does that make sense? For example, Bach seems to like repeating downward scales on successively incrementing steps; building tension upward with the key, while descending melodically.