Guess this is a form of serial music; should I declare here a "patent" on it, or maybe someone else had the idea before ?

- First, solve one or more Sudoku puzzles - giving a grid of numbers 1-9 with row, column, sub-square and sometimes diagonal constraints.
- Then, play numbers on diatonic scale (e.g. 1=C, ... 8=C', 9=D') - there was a kids' method using that. The 3/4 waltz rhythm 'jumps out' of the grid.
- One can play 2 hands too, using two consecutive lines (and ignoring the third). Or play at similar places in two Sudoku puzzles one above the other.

Hours and hours of play... and it sounds slightly less 'random' than, say, Schoenberg because it uses diatonic scale and the intrinsic constraints of solved Sudoku, almost like a strange poem format.

Doesn't stuff like this take all the talent needed out of composing? Anyways, interesting idea!

Not necessarily. Take the 12-tone system. If you treat it as a formula, you get the music you deserve. If you use the system, with talent, imagination and musicality, it's possible to create music that sounds like you and no-one else. It's also possible to create a masterpiece like the Berg violin concerto!

Well, one can choose among hundreds or thousands of Sudoku solutions. Some are bound to sound better than others when 'played'.

The next challenge would be to have a deliberately musically composed piece with the Sudoku constraints - then made into a normal Sudoku puzzle to be solved...

Poets toiled for centuries for sonnets or rubayats or other quite restrictive formats.

This kind of thing is fun (very nice idea by the way) but personally I find the music a little impersonal. Better to do what Currawong describes and use a system as the basis only, and then let your imagination and skill go from there.

Someone else on this board was composing music based on prime number sequences.

A bit more than "hundreds of thousands" actually. 6,670,903,752,021,072,936,960 to be exact.

I'm sure someone could make great music using a system like this. But as Currawong said, this person would have to put in some creative effort, not only read it as a formula. I think the repetition of C and D is a bad idea though. Would make the pieces center too much around those pitch classes. Surely you would be allowed to make octave transpositions, so you don't need an 8 to get to high C?