I've never been able to figure this out, may someone here with a musical theory background can shed some light on this...

On a keyboard, why are there 7 white notes per octave, but only 5 sharps/flats? Wouldn't it make sense to have 7 for both? I've been told "well, there just isn't" ..... and that doesn't quite answer my question....

#iConfuse

 

If you remove the idea that any notes are sharps/flats and simply think of the scale as an octave comprising twelve intervals then maybe that will make more sense to you. However, depending upon which musical cultural background you are versed in there can be more or less than 12 intervals in the scale. It's pretty much a mathematical and physics issue more than a musical one, it just so happens that the maths tend to add up to what we regard as music. For more understanding read about tunings and temperament.

 

Here:
https://en.wikipedia.org/wiki/Musical_tuning
https://en.wikipedia.org/wiki/Musical_temperament

 

That's it, just think of them as 12 equal notes. The rest is history.. literally.

 

the skull and frog are absolutely right:

just a bit info regarding the keyboard: the interval (= the jump in pitch) from a white key to it's next black key is a half tone (eg. C to C# is a half tone). the interval from the E to F key and B to C Key is already a half tone (an E# sounds exactly like the F key) so there is no need for a black key there to play the interval of a half-tone.

the reason is the so called Well-Tempered tuning. if you tune your keyboard or other instruments a different way, or choose a diffrent number (not 12) of notes per octave you indeed would need more keys. if i remember correctly the number would be 52 white keys and no black keys per octave if you would want to tune it mathematicly correct (thats not very comfy to play).

 

if they were 7 tones for both natural notes and sharps/flats, it would be of equal value in sound, and there would be more strings involved depending on the instrument to accommodate such an approach, while this approach may sound logical, it would be hard to get a logical sound in scaling, it would sound perhaps out of tune even, trying to reach closure, a resolved sound, trying to create a scale, a set of intervals that sound whole, complete, it wouldn't work out to well in sound. There is a theory that uses numbers instead of letters, I forget what it was called but, it's like simple math, perhaps that might help.

 

I don't know where I read it or how I got this (I could be wrong), that the 7 intervals that comprise the major scale, the famous do, re, mi, fa, sol, la, and si, are the easiest, most natural intervals for the western-cultured ear to pick on and feel gratified with, although reality is that the tempered scale is 12 notes, not 7. The accidentals are there to fill the gap to complete the standard 12-interval scale.

 

Interesting. So it *could* have been 6 regular notes & 6 corresponding sharps....but that wouldn't have fit 7 notes per scale cleanly (e.g. for C major).

 

Sounds like a good name for a pub

 

If I undestand your question, there are 8 sharps. 7 plus a repeat at the octave. You can play C# Major C#D#E#F#G#A#B#C#. You could play an E# Major scale but it would be easier to think F Major FGABbCDEF.
If your asking about the formula for why a Major scale is WWhWWWh step that's another question that I would be glad to answer.

 

No, that's not a random thing, it's historical. Just read about it and you'll know how things evolved.

If the system wasn't divided into equal parts, you wouldn't be able to play the same thing in all keys.

 

please let me know too about it, tell me in the simple way

 

Putting aside the brain melting math theory behind it, I think keyboard instruments were designed the way they are because it's easier to memorize the layout when there are differences in the keys and of course it makes it easier for our hands to fit. Not only are the black keys shorter and thinner, you might be surprised to know that they line up with the white keys differently.

Notice how unlike some crappy diagrams that don't show it, a real piano has the G# right in the middle of G and A, while the other blacks are offset. It's all according to a master plan!


(Picture stolen from some persons youtube)

 

It doesn't take much to know that your theory is flawed.

Besides what's already been said, there are many other instruments that don't even have keys.

 

Yep I'm off down there now for a pint of turtle juice.

 

Bro just watch this!

 

"please let me know too about it, tell me in the simple way"

OK, let's take a C Major scale. CDEFGABC. No sharps or flats. The formula to spell you scale is Whole Whole Half Whole Whole Whole Half step or WWhWWWh. C-D Whole step D-E Whole step E-F half step ect... easy right. Well our Major scale is actually referred to as an Ionion mode since it is based off the Greek modes. Our relative minor scale of C Major would be A minor or A Aeolian. It is spelled exactly the same way, no sharps or flat except it starts on A. ABCDEFGA. The same scale right? Well yes and no. It is spelled the same but the formula for it would be HhWWhWW.
Then you could have D Dorian E Phrigian ect... all based around the same spelling, no sharps or flats.

I think the original poster might have been touching on how the modes came about. The is basically thanks to the Greeks figuring out what sounded good or pleasing to their ears. I hope that help clear things up a little. If not, I will try and answer the best I can.

 

I always wandered, why there are 12 notes in a scale (keys) when we have 10 fingers

...aliens involved perhaps ???

 

EDIT:
thanks @badman for the link... nice documentary

 

Imagine keyboard as: white - black - white -black and so on to 12... instead typical 2 + 3 black keys, it will be 5 in a row and now you can ask yourself: how can you recognise octaves or any key on keyboard