when writing accidentals within say the key of...F, would you write all accidentals as flat because of the Bb in F major? Or does it depend on the direction you are going, such as if you are ascending, you would use a sharp, or if you were descending, you would use a flat?

If the first case is true, what about if you were in the key of C major/A minor, since it doesn't contain sharps or flats?
Quote by JoshXXXXX
when writing accidentals within say the key of...F, would you write all accidentals as flat because of the Bb in F major? Or does it depend on the direction you are going, such as if you are ascending, you would use a sharp, or if you were descending, you would use a flat?

If the first case is true, what about if you were in the key of C major/A minor, since it doesn't contain sharps or flats?

If you're talking about notes in chords, the name of the chord will determine whether or not you've used the correct notation.

In terms of scalar movement, usually sharps are use while ascending and flats while descending if they are in different measures; a run might look like A B C C# D E D Db C B A or something similar. That's a VERY general guideline though, it will most certainly not apply all the time when more exotic or altered scales are brought into the equation.
I don't know if this is correct, but I think it depends on the Key? If there's a flat in that key, then you don't have to write that note as b everytime, it's just understood. Now, if you put a flat next to the B, I think it would become an A, and not an A#.

I don't know if I completely understood what you were asking, so if I'm wrong, just ignore me :P
ESP: LTD EC-50
Crate GTD65 Amp
RP80 Modeling Guitar Processor

Jack White:
If you think holdin' hands is all in the fingers
Grab a hold of the soul where the memory lingers.
Accidentals are almost always written in the direction of their resolution (sharps for ascending motion, flats for descending motion). That's regardless of the approach, or anything else.

So, if I'm in the key of C, and I'm playing a D in the melody, and I'm going to a semi-tone above G, what accidental do I want to use? If it resolves up (to A, for instance), then G#, if it resolves down, then Ab.

90% of the time these tones resolve... though you may see, or write, a delayed resolution (as much as a few measures later) -- the more you see this, the more it makes sense, but don't worry about it too much.

There are two exceptions to this:
1) If the intent is specifically as an unresolved tone, this doesn't apply. This includes voice exchange, voice transfer, etc. In the cases of voice exchange/transfer, displacement, etc., you would use the accidental that makes sense in the resolving voice.

2) When it doesn't make sense. You want to write music to be clear to other people... if it's a bloody nightmare to read because you used the 'theoretically correct' accidental, use the other one. An example of this would be something like a long written trill between two semi-tones, that eventually resolves. Another example would be a three semitone chromatic passage that alternates in direction -- you'd want to pick one of the accidentals, generally, and just stick with it.

Ed: In the second case, prefer naturals over other alterations, if it applies.
Quote by les_kris
Corwinoid is God
I'm not even God-like... I've officially usurped the Almighty's throne.