The names of the notes played in sequence are "circular" - after you reach G the next natural note you come to is A.
- The intervals, or musical distances between notes are called half-steps and whole steps. The notes B and C are always just a half step apart, as are E and F. All the other notes are a whole step apart (when played in sequence) so there is a note between them, called a sharp (#) or flat (b) depending upon the "key" a song is written in.
- The Major Diatonic Scale is the basis of virtually all American popular music (except jazz). This "do-re-mi" sounding sequence of notes must adhere to a a basic formula of construction with specified intervals between the notes. It goes like this:
Keeping in mind those half steps that are always found between B and C & E and F, if we start a 1-octave diatonic scale on C and go through the notes in order, arriving at the next C, we see that those notes all "fit" perfectly with the above formula. So we say the the Key of C Major is the "natural key" - no notes need to be raised (sharped) or lowered (flatted).
(Don't worry - we're going somewhere with this! We'll get to the chords soon, but first....)
So theoretically, if all the notes were the same distance apart, we could start anywhere on the circle of notes, play seven more in sequence arriving at the same letter name we started with, and we would have a Major Diatonic Scale. But alas, this is not the case, thanks to those pesky smaller intervals between B and C, E and F. Suppose we started on G and went through a complete octave, which would look like this:
G - A - B - C - D - E - F - G
But when we apply The Formula above you'll see we run into a problem. The Formula says that the interval between the 6th and 7th note has to be a whole step - but E and F fall there! And we know that E to F is a half step! What to do.... Well, we have to make that interval "bigger." So instead of playing an F natural, we raise that note a half step to F-sharp (F#). Now we have the required whole step between the 6th and 7th notes.... and best of all, by virtue of raising that F to an F#, we now have the required half step between the 7th and 8th note! So: The Key of G Major has one sharp (F#) and the G Major Diatonic Scale goes like this:
G - A - B - C - D - E - F# - G
(This would be a good time to take out your guitar and assuming you know the names of the notes in at least 1st position, play a 1-octave scale from one G to the next, first with all natural notes and then with an F# instead of an F natural. Hear the difference? Hear how the F# sounds "right"? )
One more example of applying the formula. Suppose we start on F and go one octave:
F - G - A - B - C - D - E - F
Now match those notes to The Formula. Uh oh. Different kind of problem. Up in G Major we had an interval that was too small and we had to make it bigger. Now we have the opposite situation. The Formula says that the interval between the third and fourth notes has to be a half step, but the notes that fall there when we start with F are A and B - which is a whole step. In other words, the interval is too big and we have to make it smaller! How can we do this? Well, there are two ways. We could raise the A to A# but if we did that we would have a step-and-a-half between the second and third notes. Not good. The other way - the correct way - is to LOWER the fourth note a half step (B becomes Bb). Now we have the required half step between the third and fourth tone, and because we did that we also accomplish having the required whole step at the fourth to fifth note (Bb to C). So..... we say that the Key of F Major as one flat (Bb), and the one octave correct diatonic scale goes:
F - G - A - Bb - C - D - E - F
Remember back in Part One how I said that some notes have two names? Well, now you know why. Even though A# and Bb are functionally the same and are played in the same place, you need to think of that note in this case as Bb.
I would urge you to work out all the keys in the form of one-octave scales by starting on each possible note - including sharped and flatted notes - and either write down or memorize (or both!) which notes are sharped, flatted or natural in all 15 possible keys. Tedious? Yes, it might seem that way. But it is essential to understand and be able to hear major diatonic scales to construct the chords that are found in each key - which is what I'll be doing in the next installment.
Peace & good music,