Tonal Chance Music?

I've been toying with an idea in my head for a long time now, and have started to put it into conception:  How could I write aleatoric music that sounds tonal? When I thought about it, the answer was quite obvious:  if I control the possible elements that are going into the piece, I will control the tonality of the piece.  Not only that, I could 'write' a composition with largely chance elements involved, but sculpt them in such a way to make something that may even sound melodious, and might even have classical forms in it.

To this end, I've started putting together some different ideas for a 3-movement piano sonata that will be written as a chance piece.  I will strive to incorporate the appropriate form by controlling elements in each section.  For my first attempt, I am going to use two different chance mediums:  rolling of dice and a chess game.

For rhythms, I will use dice to determine which of several sets of measures to use for different sections in the piece.  I will create different charts with 11 different possibilities (numbers 2 to 12) and have each rhythm represent a possible number from the dice.  As certain numbers are more likely and certain numbers less, I will strategically place the rhythms to help define certain sections.  For example, in the 2nd movement, I want to create the Da Capo Aria form, and so the A section will have the least likely rhythms for this section be faster rhythms.  These will correspond with '2' (snake eyes) or '12' (double six) which each only have one possibility of being rolled.  To contrast, the B section will incorporate different rhythmic styles and will place some faster rhythms in more likely spots.  In the first movement, the first theme will use one set of rhythms and the second theme another contrasting set.  This will help give the contrasts between these two sections.

The chess board will be set to have certain pitches represented by where a chess piece lands.  White will be top hand and black will be left.  Since a chess board is 8x8, it will be perfect to use to make a tonal piece:  one full octave across the board.  After doing a little reading, it seems that the most likely positions for pieces to move will be toward the center, and so important pitches (DO and SOL) will be placed mainly here.  In addition, different pitch sets will be used to create the different tonal areas that are used in Sonata-Allegro form to help define themes.

Results will be posted soon on how this all works!