As I was thinking (oh man I am dangerous when that happens) ....the 12 factorial assumes all notes are available at all times....but as western music likes its songs in coherent keys, it becomes

8 factorial = just over 40,000 unique combinations

add say one dissonent note in your song

9 factorial = just under 363,000 unique combinations

be daring and add 2

10 factorial = just over 3.6 million unique combinations


Conclusion?

Dare to dissonate


If writing ever becomes work I think I'm going to have to stop