The Geometry of Musical Chords
music.princeton.edu
music.princeton.edu
Mathematics and Music (by David Wright) http://www.math.wustl.edu/~wright/Math109/00Book
Theory and Techniques of Electronic Music http://crca.ucsd.edu/~msp/techniques.htm
http://www.ted.com/index.php/talks/benjamin_zander_on_music_...
(Although as you probably know it's not exacly _about_ the prelude; Zander illustrates his point by playing the prelude.)