Differences between Sharp and Flat notes

In D major, the third degree of the scale cannot be Gb, as there's a G in the scale. So it has to be F#. Same for all other keys; Bb major is not called A# major because there's an A in the scale. Same for the third degree of F major. And so on, and so forth; that's what I've been told.

Makes sense, but it seems incomplete. What's missing? Is that it? Is that the only reason? If that's the only reason behind whether a note is sharp or flat, I don't see how, musically, there can be any difference between an F# and a Gb. Seems like the only difference is its name. Ab minor has a Cb...

Then again, I'm ignorant. Enlighten me!

From what I understand it's more of a theory thing, rather than a practical thing.
There might be SOME differences in other uncharted instruments.

That's all I've gathered from hearing around... it's all speculation really. Wait for someone who knows their thing...

Think of how chords are built. The 3rd of a Major chord is flattened to give us a minor chord.

Example

C Major chord = C E G
C minor chord = C Eb G

Its the quality the note provides that makes it sharp or flat, in that sense it matters what the note is called. The circle of fifths is a good place to start for trying to understand this.




As you can see on this example, the key of C Major has no sharps or flats. Clockwise we have sharps, anti-clockwise we have flats. Make chords from these scales and you will get the idea of why something is raised or flattened.

Yea, that's the theory aspect.

Are there any instruments that make a difference between a sharp and flat note though?

Stryfer wrote:Yea, that's the theory aspect.

Are there any instruments that make a difference between a sharp and flat note though?

Eh all of them? I dont really get your question sorry

Let me explain it a different way. When you play a major scale, lets say C Major, doe ray me fa so law tee doe, that sounds the same no matter what major scale you play right? When you play that scale in the next key up G major which is a fifth up from C (Circle of Fifths) its the same sounding scale just in a different key. You are raising the 7th note GABCDEF#, thats why its a F sharp and not a G flat, the note itself is sharp not flat. Does that make sense?

That makes sense, yeah. I already understood that whether the note is sharpened or flattened dictates whether the note is sharp or flat; I was mainly wondering what makes an F# actually sound different to a Gb.

I think I get it. It's not the note itself, it's the effect it has on the other notes. Is that right?

That circle picture just made this the best thread ever.

Pip clarified my question. So, it may be stupid, but I'm a bit ignorant:
Is there an instrument (let's say non fretted, like a flute or saxophone) where you would hold something or do something to create a F# and something different to create a Gb?

Well, sharps and flats are the same on a bass and most other instruments because those instruments don't use the exact ratio's for music notes.
As you may know, a note has a certain frequency. All intervals are defined in terms of frequency ratio's, which for octaves is 2:1. So for example, take the A with a frequency of 440 Hz. The A an octave above that has 880 Hz, and the one below 220 Hz. Still with me?
A perfect fifth has ratio 3:2. If we were to construct a perfect fifth on the same A (440 Hz), then we'd end up with a frequency of 660 Hz. As you should know, this corresponds to an E.
However, instruments are tuned using something called 'Equal Temperament', which is a fancy way of saying that they just take the double rule for octaves and then chop up the interval in piece of equal size. The math is a bit annoying, but it turns out that an E on an instrument will be just over 659 Hz!

Now, what has this to do with flats and sharps? Well, simple. A sharp is defined by a ratio as well (it's 16:15, I believe). To get a flat, you just 'subtract' a sharp (it actually corresponds to dividing and multiplying). Taking again A (440 Hz), a perfect B would be 488.9 Hz. If we now take A#, that would be 469.3 Hz. If we take Bb, that would be 458.3 Hz. I think you see that an A# is not the same as a Bb. In theory, at least, since instruments circumvent this problem by using equal temperament tuning.

I hope that was clear.


EDIT: Stryfe, that is possible. Two classmates made a piano tuned in equal temperament, but with 30 tones instead of the usual 12. They had different keys for the Gb and F#.

That's the explanation I was asking for in terms of sound!

I thought there had to be a reason why theory began to distinguish between the two. Otherwise it just seemed to just needlessly complicate things.

It's going to take me a while to understand that properly, but I have a grasp on it.

Could you explain the frequency ratios a bit more? I've forgotten most of what I learned at school about ratios...

I also don't really get...

Well, simple. A sharp is defined by a ratio as well (it's 16:15, I believe). To get a flat, you just 'subtract' a sharp (it actually corresponds to dividing and multiplying).

I highly doubt your explanation is the problem, it's my brain that's the problem

A frequency ratio of 2:1 means that multiplying the frequency of the first note by 2 is the same as multiplying the frequency of by 1.
So for an octave on 440 Hz (ratio 2:1): 2*440=880, and 880*1=880, hence an octave on 440 Hz has frequency 880 Hz.

A frequency ration of 3:2 means that multiplying the frequency of the first note by 3 yields the same answer as multiplying the frequency of the second note by 2.
So for a perfect fifth on 440 Hz: 440*3=1320, and 660*2=1320, hence a perfect fifth on 440 Hz has frequency 660 Hz.

Now for a semitone (16:15) on 440 Hz: 440*16=7040, and 412.5*15=7040, hence a semitone above 440 Hz has frequency 412.5 Hz.

Got it.

What about the 'subtracting a sharp to get a flat' business?

Well, to get a flat on a bass, you just go down one fret. This means that the distance between the flat and the actual note equals one semitone, or one sharp, so that's why I said 'subtracting a sharp'. Should've subtracting a semitone, since a sharp is adding a semitone.

Ah right, and subtracting a semitone from A does not give the same frequency as adding a semitone to G. That right?

Exactemundo.

I'm gonna have to write all this down so I remember it better...