Lessons from one of Bach's Chorale Preludes - Discussion

http://imslp.info/files/imglnks/usimg/f/fa/IMSLP00813-BWV0684.pdf

I have posted this piece in Rep or Suggest a work but I think this merits a discussion - open to all levels but geared to assist late beginner and intermediate composers. You should be comfortable reading music and enough understanding of harmony and counterpoint to identify some features of this work - so the basics should be understood.;See the score above and follow it. Note the long notes in the bottom staff - this is the pedal line. First thing to do is take all the phrases and connect them (eg remove the rests).

Second determine the relation between the running sixteenths in the bass and the pedal line. Ask yourself what is happening and if adventurous identify the neighbor, passing and "escape" tones.

Third determine what is happening in the top staff the majority of the time. What functions do they serve. Explain the exceptions and what purpose they serve.

Finally there are three levels of rhythmic units which overlap. What are they? What would you say is the primary beat of this work (eg is it the half note, quarter, eighths, etc)

Here is an OK recording of it (BTW as I am finding out from my own experience this is a very difficult piece to play well!):

And a bonus to hear a similar treatment in some ways but from Bach's Cantata 7: