The Concept behind Scales by: David from www.piano-play-it.com
Hi Prasad,
As piano players we're trying to feel at home with all different scales in order to be able to play pieces in all different scales.
Take the moonlight sonata for example.It's written in the key of C#m and is moving through the piece to a few different scales.
Now playing a piece with four sharps is not so easy if you don't control this scale, and therefore I suggest to practice all 12 scales before we approaching such a piece.
When speaking about Jazz and Pop you must remember that singers for example, feel comfortabley only in a few certain scales.
And one day their throat might soar for example and all of a sudden you'd have to accompany them in a lower scale then usual.
Then it's very handy to have a full control at all piano scales as well.
Now Why did the composers wrote their pieces in different scales?
The answer to that is that earlier in history the piano was tuned very differently. I'll post an article that discusses this isse fully pretty soon.
The scales in pieces by Bach before the whole tempered clavier for example, were chosen according to that factor.
Anyways, When a composer wanted to choose a scale that would express a gloomy feeling in his piece he'd go for a certain scale and if he'd like to choose a brighter scale he'd go for the other.
Try to play the A minor scale and C# minor scale for example. Both are minor scales but A minor has only white keys while C# minor has four sharps.
The sound of these scales and their location on the piano are different and therefore the vibe created by using them is todally different.
In India by the way, scales have an important ceramonial effect. So when you wake up you'll be playing an improvisational piece with a certain scale and in evening time you'll pick the other.
As for your second question.. it's very broad since songs are composed in many ways. But mostly when a singer composes a song he will choose a piano scale he's comfortable with.
That has to do with the range of his voice and his control over his instrument. When you compose a song on the piano or on the guitar you will naturally choose a different scale since it will be more comfortable to play a certain scale on guitar rather then on a piano.
I hope I helped you. If you have further questions, don't hesitate to ask me.