# What makes difference between flat and sharp in scales?



## jamesnnnnn

for example in g minor, it is wrog to say that we have an A#, because it is called Bb.
Why is it called a Bb in a G minor, and where is it called A#, as for this note, so for all of the blacks, and also whites as Cb, E#....


----------



## Taggart

G minor shares a key signature with B flat major.. Theory talks about relative major / minor keys. Because you have B flat in the key signature that's what you you use.

When you come to raise the 7th it has to be F# because the next note will be G. Also the # points out that the 7th is being raised.


----------



## Ralphus

As Taggart said.

Also, there are other rules or tendencies, often followed for consistency or to aid readability.

1) use sharps going up, flats going down (E.g. chromatic scale)

2) if you're 'raising' a note, use a sharp (don't flatten the note above!); likewise use flats when lowering. That's because you're altering a certain degree of the scale and you should stick with the same letter name. Same with double sharps and double flats. If an F# is raised, it raises to F##. We have to call it that (rather than the G it actually sounds as), esp. if we also have a G#, otherwise we'd have to constantly be changing Gs to sharp or natural: very confusing to read.

3) other than raised notes, use all sharps or all flats depending on the key you are in; don't mix them together unnecessarily. 

Musicians get used to reading certain ways of notation. Of course, composers can change the conventions when they want to, but it can be tough on the reader. I recently played a quartet by Jean Cras in which he used an A major key signature but with an A# added (that is, a key signature with 4 sharps but the 4th sharp being A, not the expected D!). It was very off-putting to read.


----------



## jamesnnnnn

Thanks guys, but....
IF I raise note its sharp, if I lower its flat...whats foundation?
From what lower, from what raise..
If I want to have G minor.. WhWWhWW, i got a scale, why Bb, why not A#, i lowered and raised nothing, as i started by formula for minor scale/mode, and thats my foundation.
Or do you take a major scale for a foundation toward building all other things?


----------



## EdwardBast

jamesnnnnn said:


> Thanks guys, but....
> IF I raise note its sharp, if I lower its flat...whats foundation?
> From what lower, from what raise..
> If I want to have G minor.. WhWWhWW, i got a scale, why Bb, why not A#, i lowered and raised nothing, as i started by formula for minor scale/mode, and thats my foundation.
> Or do you take a major scale for a foundation toward building all other things?


In any scale, each degree is a second above the last. Spelling a G minor scale beginning with G-A-A# violates the rule because A-A# is not a 2nd, it is an augmented unison.

More generally:
Each major or minor scale uses all seven letter names (A, B, C, D, E, F, G), one for each of its seven different scale degrees. This is a fundamental law of common practice tonal music, and of modal music. A change in letter should indicate a _change_ in scale degree, as opposed to an accidental, which indicates an _alteration_ of a scale degree. B-flat is the third scale degree of G minor, G to B-flat being the interval of a minor 3rd. G to A# is an augmented _2nd_, so A# would not be used for the _third_ scale degree. it is a misspelling. It indicates the raising of the second degree which, by the way, makes no sense in G minor.


----------



## Ralphus

> If I want to have G minor.. WhWWhWW, i got a scale, why Bb, why not A#, i lowered and raised nothing, as i started by formula for minor scale/mode, and thats my foundation.


G minor is the relative minor of Bb Major. It shares the same key signature. The key signature says Bb.

Also, as EdwardBast explains, you need 1 of each letter name: G (natural) minor = G A Bb C D Eb F G. If you for some reason ignored the key signature and used A# it would look like: G A A# C D Eb F G. That is, 2 "As" and no "B".


----------



## amfortas

Also, depending on the tuning system you're using or the instrument you're playing, an A# may not be exactly the same note as a Bb.


----------



## SixFootScowl

amfortas said:


> Also, depending on the tuning system you're using or the instrument you're playing, an A# may not be exactly the same note as a Bb.


Now that is a key point!


----------



## Bettina

Florestan said:


> Now that is a key point!


Yes, he made quite a sharp observation!


----------



## amfortas

Bettina said:


> Yes, he made quite a sharp observation!


But yours fell flat.

I'll be here all week.


----------



## hpowders

amfortas said:


> But yours fell flat.
> 
> I'll be here all week.


Is that a promise or a threat?


----------



## tortkis

jamesnnnnn said:


> for example in g minor, it is wrog to say that we have an A#, because it is called Bb.
> Why is it called a Bb in a G minor, and where is it called A#, as for this note, so for all of the blacks, and also whites as Cb, E#....


In the 12 Equal Temperament, G-Bb and G-A# sound exactly the same. But the minor third in 12ET, whose ratio is 2 to 3/12, or 300 cents, does not sound pure, because the interval is not a simple ratio. The closest pure interval is 6/5, or 315.641 cents, which is wider than 12ET minor 3rd.

In order to make an interval sound better, strings players used the pitches as shown below. (This is not possible with keyboard.)

A < A# < Bb < B

When you play a minor third on G, if you play G-Bb (in this tuning,) the interval is larger than 300 cents, which is closer to the pure interval 315.641 cents. If you play G-A#, the interval is smaller than 300 cents, which is further apart from the pure minor 3rd.


----------



## KenOC

Perhaps I am misunderstanding. I had thought that with equal temperament, each of the twelve notes of the scale has a frequency equal to the twelfth root of two times the frequency of the preceding (lower) tone. So a full octave of twelve tones brings us around to a doubling of the frequency.

In this sort of system, the relations among the tones are identical regardless of the key signature. And it never matters whether we call a tone G-sharp or A-flat. Thus:

A 440
A#/Bb 466
B 494
C 523
C#/Db 554
D 587
D#/Eb 622
E 659
F 698
F#/Gb 740
G 784
G#/Ab 831
A 880


----------



## EdwardBast

KenOC said:


> Perhaps I am misunderstanding. I had thought that with equal temperament, each of the twelve notes of the scale has a frequency equal to the twelfth root of two times the frequency of the preceding (lower) tone. So a full octave of twelve tones brings us around to a doubling of the frequency.
> 
> In this sort of system, the relations among the tones are identical regardless of the key signature. And it never matters whether we call a tone G-sharp or A-flat. Thus:
> 
> A 440
> A#/Bb 466
> B 494
> C 523
> C#/Db 554
> D 587
> D#/Eb 622
> E 659
> F 698
> F#/Gb 740
> G 784
> G#/Ab 831
> A 880


Correct ^ ^ ^. This is about notation and function, not pitch.


----------



## amfortas

KenOC said:


> Perhaps I am misunderstanding. I had thought that with equal temperament, each of the twelve notes of the scale has a frequency equal to the twelfth root of two times the frequency of the preceding (lower) tone. So a full octave of twelve tones brings us around to a doubling of the frequency.


Yes, but . . .

In _How Equal Temperament Ruined Harmony (and Why You Should Care)_, Ross W. Duffin argues that equal temperament didn't become the universal standard until about 1917.

And as has been pointed out above, even now string players will sharpen or flatten leading notes within the tonal context, so that the difference between an A# and a Bb isn't just a matter of terminology.


----------



## Petwhac

amfortas said:


> Yes, but . . .
> 
> In _How Equal Temperament Ruined Harmony (and Why You Should Care)_, Ross W. Duffin argues that equal temperament didn't become the universal standard until about 1917.
> 
> And as has been pointed out above, even now string players will sharpen or flatten leading notes within the tonal context, so that the difference between an A# and a Bb isn't just a matter of terminology.


Never mind what string players do. If you play C and F sharp it's an augmented 4th. If you play C and G flat it's a diminished 5th.
They both sound the same and they are the same aurally.


----------



## Guest

Basically, you don't want to skip steps in the scale. So you wouldn't go, say, Bb B C D E F G Bb, right? So you would use A# so that you're hitting all the steps A# B C D E F G A#. Now, that's not a real scale but you see what I'm getting at, I hope.

However, I worked with a blues guitarist once who wrote blues scales down for me and did it that way--going from Bb to B--and it works well enough.

In jazz, it is very common to use Bb when descending from B and to use A# when ascending for A in the same piece. So none of this is graven in stone.


----------



## Petwhac

Victor Redseal said:


> Basically, you don't want to skip steps in the scale. So you wouldn't go, say, Bb B C D E F G Bb, right? So you would use A# so that you're hitting all the steps A# B C D E F G A#. Now, that's not a real scale but you see what I'm getting at, I hope.
> 
> However, I worked with a blues guitarist once who wrote blues scales down for me and did it that way--going from Bb to B--and it works well enough.
> 
> In jazz, it is very common to use Bb when descending from B and to use A# when ascending for A in the same piece. So none of this is graven in stone.


Notation is a matter of convention. If I'm handed a jazz chart to play from I'd much rather see Bbmin7 and Ab7 than their equivalents A#min7 and G#7 even if in the context of the key of the piece they're incorrectly spelled.


----------



## EdwardBast

amfortas said:


> And as has been pointed out above, even now string players will sharpen or flatten leading notes within the tonal context, so that the difference between an A# and a Bb isn't just a matter of terminology.


Which makes it all the more important that our OP learn the standard notation conventions. Don't want those violinists sight-reading A# only to find out a measure later they should have been playing B-flat!


----------



## millionrainbows

Simple, simple answer that _all _of you should have mentioned:

A 7-note diatonic scale (like we use) must have 7 _different_ letter names, with no repeats; also, no double-flats or double sharps.

Question: why is there no "F flat major" scale?

Because it is E major. E-F#-G#-A-B-C#-D#-E.

If it started on Fb, it would break the rules:

Fb-Gb-Ab-Bbb-Cb-Db-Eb-Fb. No double-flats, and it must be a sequence of 7 different letter names with no repeated letters.

It could not be Fb-Gb-Ab-A-B-C#(Db)-D#(Eb)-Fb. It has 2 A's (Ab and A natural).

As you can see, scales must be all flats or sharps, not a mixture of the two. The only way to maintain this requirement is to have no repeated letter names.


----------



## amfortas

Petwhac said:


> Never mind what string players do. If you play C and F sharp it's an augmented 4th. If you play C and G flat it's a diminished 5th.
> They both sound the same and they are the same aurally.


Right. So long as you never mind what string players do.


----------



## millionrainbows

amfortas said:


> Right. So long as you never mind what string players do.


Or unless you're a keyboard player playing with fretted instruments, or a choir, or violins. Bach supposedly carried extra keyboards in his hay wagon for this purpose. He was a big advocate of going towards "well" or equal temperament. Fretted instruments may have paved the way for ET.


----------



## Petwhac

millionrainbows said:


> Simple, simple answer that _all _of you should have mentioned:
> 
> A 7-note diatonic scale (like we use) must have 7 _different_ letter names, with no repeats; also, no double-flats or double sharps.
> 
> Question: why is there no "F flat major" scale?
> 
> Because it is E major. E-F#-G#-A-B-C#-D#-E.
> 
> If it started on Fb, it would break the rules:
> 
> Fb-Gb-Ab-Bbb-Cb-Db-Eb-Fb. No double-flats, and it must be a sequence of 7 different letter names with no repeated letters.
> 
> It could not be Fb-Gb-Ab-A-B-C#(Db)-D#(Eb)-Fb. It has 2 A's (Ab and A natural).
> 
> As you can see, scales must be all flats or sharps, not a mixture of the two. The only way to maintain this requirement is to have no repeated letter names.


The scale of G# major would have an F double sharp as its 7th degree. Are there no examples of pieces with that key sig?


----------



## Ralphus

> Simple, simple answer that all of you should have mentioned:
> 
> A 7-note diatonic scale (like we use) must have 7 different letter names, with no repeats; also, no double-flats or double sharps.


Several of us have mentioned that a scale must use 7 different letter names.

We also use minor scales. A G# harmonic minor scale requires an F##. As does G# melodic minor. Not in the key signature, but that was not the issue. If we write out the scale we will include an F##.

A major scales follows the pattern tone--tone--semitone--tone--tone--tone--semitone. It's common in theory exercises to have students build major scales following that pattern from any letter name, including potentially F-flat. I know that _key_ doesn't exist in reality, as a tonality, but can exist theoretically as a scale. Remember, too, that C# major and D-flat major happily co-exist, despite the fact they will sound the same (all other acoustical arguments ignored). If one scale didn't exist solely because it _did_ exist in its enharmonic equivalent form then either C# or D-flat major wouldn't need to exist. But they both do.

As others have pointed out, there are differences between conventions of notation and acoustical issues related to tuning and temperament. I believe the OP was asking about notation.

Regarding tuning issues, musicians will alter the pitch of a note depending upon the harmonic context in which it exists. If I play the third of a chord with a trio and then sustain that note while my colleagues alter their notes around me to create a different chord, I may have to subtly alter the tuning of my note even though on paper the B-flat it was in the first chord should sound the same once it becomes an A# in the context of the second chord. The reality is that temperament and instruments are not perfect. But this is a separate issue to conventions of notation.


----------



## amfortas

millionrainbows said:


> Or unless you're a keyboard player playing with fretted instruments, or a choir, or violins. Bach supposedly carried extra keyboards in his hay wagon for this purpose. He was a big advocate of going towards "well" or equal temperament. Fretted instruments may have paved the way for ET.


But you're not equating "well tempered" with equal temperament, are you?


----------



## Guest

Petwhac said:


> Notation is a matter of convention. If I'm handed a jazz chart to play from I'd much rather see Bbmin7 and Ab7 than their equivalents A#min7 and G#7 even if in the context of the key of the piece they're incorrectly spelled.


I'm talking about playing individual notes for soloing or walking not chords. Chords are a different matter.


----------



## millionrainbows

Petwhac said:


> The scale of G# major would have an F double sharp as its 7th degree. Are there no examples of pieces with that key sig?


First, you need to memorize all the key signatures.

Sharps: C-G-D-A-E-B-F#-C#, by number of sharps. C has none, G has one sharp, etc.

Flats: C-F-Bb-Eb-Ab-Db-Gb-Cb.

There is no "G# major;" it is called Ab major.

If it were, it would fail the test: G#-A#-B#-C#-D#-E#-F##.

Also, look at these on the circle of fifths, and know that going counterclockwise is the "circle of fourths."

Also, note the "overlapping keys" shared by both: C#/Db, F#/Gb, and B/Cb. "B" is a sharp key, spelled in sharps. "F" is a flat key, spelled in flats.

Beyond the "7" limit (7 sharps or 7 flats), errors occur. We don't need those anyway, since the system begins to overlap back on itself anyway.

The best explanation I've seen is in The Guitar Grimoire, I forget which volume.

The whole idea of key signatures is based on the 7-note diatonic scale. Guitarists have to figure this stuff out from scratch.


----------



## millionrainbows

amfortas said:


> But you're not equating "well tempered" with equal temperament, are you?


"Well" tempering was Bach's system of tuning wherein all 12 keys sound passable. This was actually an early form going towards equal temperament, which was not achieved until the early 20th century (1919 or something). This is because we could now electrically measure frequency. Before this, tuners counted beats using a stopwatch, which was not precise. Bach did it by ear. See his method:

larips.com


----------



## Bettina

millionrainbows said:


> Simple, simple answer that _all _of you should have mentioned:
> 
> A 7-note diatonic scale (like we use) must have 7 _different_ letter names, with no repeats; also, no double-flats or double sharps.
> 
> Question: why is there no "F flat major" scale?
> 
> Because it is E major. E-F#-G#-A-B-C#-D#-E.
> 
> If it started on Fb, it would break the rules:
> 
> Fb-Gb-Ab-Bbb-Cb-Db-Eb-Fb. No double-flats, and it must be a sequence of 7 different letter names with no repeated letters.
> 
> It could not be Fb-Gb-Ab-A-B-C#(Db)-D#(Eb)-Fb. It has 2 A's (Ab and A natural).
> 
> As you can see,* scales must be all flats or sharps, not a mixture of the two*. The only way to maintain this requirement is to have no repeated letter names.


Great explanation! I'd just like to add that many of the harmonic minor scales actually do mix sharps and flats. I know that those don't count as diatonic scales, but I wanted to mention this exception to the rules that you've clearly laid out here.


----------



## millionrainbows

God, I'm glad I said "diatonic."

We can look it up in WIK. It says that G# minor uses the B major signature of 5 flats. When harmonic minor is used, F## is necessary. 

These are weird exceptions. The guidelines I gave are a way of simplifying the whole thing, without all the exceptions and special cases.


----------



## isorhythm

This thread raises a point that's often missed in discussions of temperament and what we've supposedly lost by going to equal temperament, namely that string players and singers find pitches by ear and consequently don't use equal temperament, probably not even when they're being accompanied by a keyed or fretted instrument.

What kind of tuning they do use hasn't been studied enough, I think. Noteworthy that sharpening leading tones is actually further from just intonation than 12TET.


----------



## Zellibrung

Petwhac said:


> Never mind what string players do. If you play C and F sharp it's an augmented 4th. If you play C and G flat it's a diminished 5th.
> They both sound the same and they are the same aurally.


It would be funny if they found out some tendency for string players to play it microtonally different depending on whether it's Bb or A#


----------



## EdwardBast

Zellibrung said:


> It would be funny if they found out some tendency for string players to play it microtonally different depending on whether it's Bb or A#


It wouldn't be funny really, it would be just what one would expect if, for example, the A# was in B minor and the Bb was in G minor.


----------

