This particular piece is in D minor. (You will definitely want your program to figure this out; otherwise you will produce the "wrong" key signature, need to in

This particular piece is in D minor. (You will definitely want your program to figure this out; otherwise you will produce the "wrong" key signature, need to include a ton of accidentals, and it will look a bit kludgy.) Anyway, in minor keys you very often see the note below the tonic get raised. So for example, in D minor, the pitch C#/Db will pretty much always be C#. You also often see the note two below the tonic get raised. I'd say a "descending melodic line" should continue past the note with an accidental, so D-C-B is a descending melodic line, for which you could make inferences about the C, but not necessarily the B. If it goes down and then immediately back up again, the note in between is (in my experience) more likely to be sharp than flat, and vice versa. As another rule of thumb, it is somewhat uncommon to have two consecutive notes with the same letter, one of them with an accidental. For example, if you have a G#/Ab, and it follows or precedes an A-natural, it is probably a G#. If it follows or precedes a G-natural, it is probably Ab. Of course, exceptions to all of the rules can be found. :)