[wcap]

I'm no whiz at music theory, but I'll add something that I think has not been said already.

A typical major scale (as opposed to a minor scale, for example) has the following intervals :

whole step, whole step, half step, whole step, whole step, whole step, half step

A half step is like going from one fret to the the next on guitar, or from one key to an immediately adjacent key on piano (in this context key refers to the physical object you press on a piano keyboard to get a sound, NOT a key signature such as the key of G, for example).

A whole step is two half steps.

I think a lot of this music theory stuff is easier to visualize if you look at a piano. If you start, say, at middle C (the white key just below the place where there are two black keys clustered near the middle of a piano keyboard) and you work up the piano keyboard playing just the white keys in order until you reach the next C (thus playing C, D, E, F, G, A, B, and then C in order), you have played a major scale. Look at the intervals you have played and you will see that you have done a whole step, a whole step, a half step, a whole step, a whole step, a whole step, and a half step.

Now, play a major scale on a piano (in other words, with the same sequence of intervals), but this time start on a G (the white key just above the lowest of the cluster of three black keys). You will notice that to get the intervals right you needed to play a black key (F sharp, the black key just above the white F key) toward the end of this scale. You have just played a G major scale (or another way of saying this would be that you have played a major scale in the key of G) - and if you built a song out of pretty much just those notes, you'd be playing it in the key of G (I'm oversimplifying somewhat here).

Start on some other white key on the piano and keep the same intervals and you will end up playing more black keys (that is more sharps or flats, depending on how you want to look at the black keys).

Minor scales (and other sorts of scales) have slightly different sequences of intervals.

This sounds more complicated than it is. But sit down at a piano sometime and see what I'm talking about. It is just so much easier to see what is going on with the scales and such on a piano than on a guitar.


(Again....when I'm referring to the white and black keys on a piano I'm referring to the white and black physical objects that you push down to get the notes, but when we talk about, say, the key of G, we are talking about building your music out of the collection of notes that you have in a major scale starting with a G note - sorry for the confusing double use of the word "key" here).


I'm not sure if what I wrote helps your understanding at all. If not, and if the simpler answer that a simple piece in the key of G will mostly use G, C, and D chords (and often E minor in bluegrass), then don't fret over my explanation (no pun intended!).