If it was up to me I wouldn't mind as a rule to write always # when the passage is ascending, and b when the passage is descending. But I have many doubts about it:
1- Why baroque or classical composers wrote # in descending passages where the 7th of the harmonic minor was involved? For example in C major they would never do: A-Ab-G, because the 7th in A harmonic minor is always G#. So they would go: A-G#-G.
2- Why composers such Mozart would respect the rule above, but in all the other cases would write both # or b for ascending or descending chromatic passages? There was any rule or was random choice?
3- If I write something in baroque style do I have to respect the rule above?
What do you guys think?
thanks