Sharp of flat?

[canudigit]

It is my understanding that a flat is notated when descending and a sharp is used when ascending in reference to the chromatic scale. Are there any other rules for using sharps and flats when notating music? This is subject to notation and not sound because C#/Db SOUND the same but are NOTATED differently.

Thanks Steve

[UKRuss]

The major scale cannot have two notes appearing using the same name.

So Fmajor

F G A Bb C D E F.

Bb sounds the same as A# but in this scale it must be notated as Bb because it refers to the perfect fourth. A# would refer to the third augmented.

Arguments abound as to the value of such things but it's a theoretical thing, and that's just the way it is.

[zog]

You are right about the chromatic scale the other generally accepted rule would be to use what is in the key signature. For example if the key signature has sharps then you would use sharps instead of flats and vice versa.

[gersdal]

There's a lot of music theory books available on the net that maybe gives the answer. Here is one that may be interesting for you:
http://a-no-ne.com/music/theory/

Russ: If you play a Db in a song that is generally in the F major scale, should it be denoted Db or C#? Or the blues note Cb? And does it matter if it is in an ascending or descending run?

[forgottenking2]

I will step in and answer Db or C# would be correct in the appropriate context, if there is no temporary tonizations or modulations then I would probably go with Db (the lowered 6th) since: 1. It is common in major tonalities to "borrow" the lowered 6th degree from minor and 2. The Major Scale with a lowered 6th is the harmonic major scale making it a logical choice. 3. If the chord happening at the time is an F Major type, C natural would already be present in the harmony, making the melody note a lot easier to read/notate as a Db.

The blue note can be either a b5 or a #11 so either B or Cb would work. Once again it would deppend on the chord going on at the time (and many times, the transcriber).

For the sake of simplicity of notation I use sharps when ascending and flats when descending. (We're talking chromatic passages right?)

Anyways, feel free to correct me if I am wrong. This is a cool subject (in a very geeky way).

-Jorge

[joeyd929]

If you are working from chords/triads it depends on the chord.

For example, if you have a C augmented it would be G#, not Ab. This is because you sharp the 5th degree to make an augmented chord.

If it was a Bb dominant 7 chord, then it would not be G#, it would be Ab. This is because you flat the 7th to make a dominant 7th chord.

IF you had a C Dorian scale then it would be Eb and Bb, not D# and A#...Again, because you flat the third and 7th degree it would be Eb and Bb.

So it depends on where you are, where you came from, and/or where you are going with it.

Same note, different context or perspective...

Hope that helps..

[UKRuss]

There's a lot of music theory books available on the net that maybe gives the answer. Here is one that may be interesting for you:
http://a-no-ne.com/music/theory/

Russ: If you play a Db in a song that is generally in the F major scale, should it be denoted Db or C#? Or the blues note Cb? And does it matter if it is in an ascending or descending run?

ah ha, now you see your making music. I did say my answer was purely theoretical.

[canudigit]

Thanks for all the input... I love these topics because if makes people think.... very good answers.....

[szulc]

If you are playing in a specific KEY then use the accidentals for that KEY.
If you are modulating to a new KEY use the accidental from the new KEY you are modulating to (if appropriate). If you are playing atonal music use sharps when ascending and b's when descending.

[JonR]

Just to echo some of the above, and expand on it....

The underlying rule here is "clarity in context". The point of notation is that it should be as quick to read as possible.
This is why (out of any context) we use sharps when ascending and flats descending - because it requires fewer use of natural signs (less clutter on the stave) , and represents an alteration of the previous note, which makes it easier to understand.

However, in key contexts, it's common (with enharmonic alterations) to use sharps in a sharp key and flats in a flat key.
So in the key of F, you might expect a Db; while the same note in the key of G would probably be written C#.

But again, it can depend on local context, esp any accompanying chord symbols.
So if the chord is G7b5, then the note should obviously be shown as Db. If the chord is A or A7 then it would be written as C#. (This would be regardless of the overall key.)

If the note is just a passing alteration of a diatonic note, it can be clearer if it's written as an alteration of the note above or below.
E.g., in notation, C-Db-C may be clearer than C-C#-C (at least it needs fewer symbols). Likewise D-C#-D is arguably easier to read than D-Db-D. (Again, though, there would be contexts where other choices might apply.)

Just remember - what looks neatest, simplest, and is easiest to read?