Bach's Prelude No.1 of the Well Tempered Clavier is a beautiful piece.  It illustrates his mastery of harmony, development and suspense.  It's like a well written thriller. 
I was working on this with a student this morning, and was so inspired, that I had to put it in my book.  Rather than photocopying the piece and putting in multiple pages of notes that I can't read when the light is not right, I decided to write out the chord symbols and use it as a basis for improvisation. 
Bach's piece is really just a bunch of rolling arpeggios, running twice through for each chord.  It's very simple rhythmically.  It's complexity lies in the harmonic movement.  Try just strumming through the chords - they have a strong sense of direction. 
I have more to learn from this tune, but I thought I would share the chord progression for anyone else who is inclined to discover it's beauty.