Al's Music Tidbits - Volume 3
by Al Shank
Last week, we derived what we call a “chromatic” scale of 12 notes that divide an octave into 12 equal intervals (sonic distances). If we count the octave of the starting note, we get 13, of course. These notes and any number of octave repetitions thereof, have become the tonal material for virtually all of our “Western” music, including country and bluegrass. However, for historical reasons, going back to the ancient Greek tetrachords (four-note segments) and the so-called “church modes”, the scales used in our music are comprised of only seven notes (eight if you count the octave of the starting note). If you split an octave up into seven intervals instead of twelve, then obviously some of them have to be larger. To construct a seven-note scale, choosing from among the twelve notes of the chromatic scale, we just have to skip over five of the twelve; we end up with five “large” intervals and two “small” ones, the large ones being twice as big. This can be done, of course, in quite a few different ways, creating different-sounding scales, which is what the modes were.
The easiest way to understand this is to picture a piano keyboard (a Bluegrass piano, of course >:-). A piano has broad, white keys that extend to the edge of the keyboard and narrower, black keys that do not. Most pairs of white keys are separated by a black key, but not all of them. The black keys are in “sets” of three, then two, three, then two, the sets separated by two white keys next to each other. Starting from any white key and counting 13 total keys in either direction will take you to an octave doubling of that first key. In any such octave, there will be eight white keys and five black ones. The notes on adjacent white keys (with no black in between) are separated by the “small” intervals, which we call “semitones”, the others by the “large” intervals, “tones” or “whole tones”. Depending on which white key you choose to start on, the whole-tone and semitone intervals fall at different points in the scale. Since there are seven distinct white keys per octave, there are seven different-sounding scales, called “modes”. Pick a white key at random and play it and then the next seven to the right. You’ve just played a scale, one of the seven “modes”. Move one key to the right of your starting white key and repeat. You can do this seven times before you will duplicate your first scale. They sound pretty different, don’t they, especially the ones with the semitone at the beginning. Now find the white key just before a set of two black keys and play that scale. Sound familiar? That’s do-re-mi-fa-sol-la-ti-do, what we now call the major scale, and the scale upon which most country and bluegrass songs are based. Also for historical reasons, those particular notes are also called c d e f g a b and c.
The major scale, then, is an arrangement of seven tones out of the twelve in the chromatic scale, such that the “distances” (intervals) between the notes are arranged thus:
whole tone (black key between whites)
whole tone “ “ “ “
semitone (two whites in a row)
If you just play white keys, then the only major scale is the one beginning on a “c’ note, a white key just before a set of two black keys. However, you can play a major scale starting from any note, white or black, but you have to make sure the semitone intervals are in the right places, which means playing some black keys. The piano is a great instrument to learn about music because the notes are all laid out in front of you, and you can see the intervals while you hear them.
On a guitar or mandolin, the frets are all a semitone apart, so playing a scale involves skipping some frets. For example, if you start on an open (unfretted) string, you would then play the notes at the 2nd, 4th, 5th, 7th, 9th, 11th and 12th frets to play a major scale.
The letters for notes, c d e, etc., are “tied” to specific actual notes, certain keys on the piano, certain strings/frets on stringed instruments, etc. However, the “solfeggio” (do re mi, etc.) or numbers (1 through 7 or I through VII) refer to positions relative to the scale, so they can be used regardless of what note is the starting point, which we call the “tonic” or “key note”. This is an extremely important and powerful point, because you can apply it to any starting note, or “key”. By learning one scale, you really learn all twelve possible major scales, in terms of hearing and singing, but not, unfortunately, in terms of playing them on an instrument.
Those letter notes are going to be used a lot, though, and we need to name the black keys, as well. Keep in mind that the semitone intervals are between e and f, b and c. Since there are chromatic-scale notes between the other major-scale notes, we need to name them. If a note is raised by a semitone, we call the resulting note “sharp” (symbol #); if it is lowered, we call it “flat” (symbol b). So, the chromatic scale is made up of:
c c# d d# e f f# g g# a a# b c
db eb gb ab bb
Note that “d-flat” is the same as “c-sharp”, “d-sharp” is the same as “e-flat”, etc. They are just different names for the same black keys.
Next week we’ll discuss intervals in greater detail and introduce the concept of chords. Any questions or suggestions for subject matter may be sent to: firstname.lastname@example.org.
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