Music Theory 101
Obviously, there may be mistakes (I’m not a music theory majorJ). There are always exceptions to the rules (hmmm, just like MTG).
There are 12 different notes in the musical scale. There are A, A# (or Bb), B, C, C# (or Db), D, D# (or Eb), E, F, F# (or Gb), G, G# (or Ab). (I think there is some special term for things like D# and Eb as they are really the same note, I just don’t know what it is). The distance between any two adjacent notes is called a half step. On keyboard instruments, this is the smallest interval that can be achieved. Smaller intervals (for example quarter steps) can be achieved on stringed instruments (like guitar) by bending but we’ll ignore those intervals. Playing a note, skipping the adjacent note and then playing the next adjacent note is called a whole step. For example, the distance between B and C, D# and E, F and F# are all half steps. The distance between and A and B, C# and D#, E and F# is a whole step. On a guitar, the distance between adjacent frets is a half step and the distance between two frets is a whole step. The other important interval is called an octave. An octave is the distance between a given note and the next higher occurrence of that same note. Technically, the next higher occurrence of that same note is vibrating at twice the frequency of the original note.
Above, the symbols # and b were used. The # is called a sharp. The b is called a flat. When you really look at printed music, the # is actually in a slightly different font and italicized. The flat symbol is not the letter b but something with a slightly pointy bottom.
Scales are probably the most important aspect of music theory as it is around a scale that chords, chord progressions, and melodies are made. There are many types of scales but the two most important from a beginning standpoint are the major scale and the minor scale. Unfortunately, there are three kinds of minor scales, but more on that later. The important aspect of major and minor scales (whichever kind of flavor) is that they can be generated from any starting note and what makes them major or minor is the pattern of half and whole steps that occurs. The nice thing about these patterns for guitar and bass players is that these patterns can then be replicated to different locations on the fret board to achieve scales in any key (this sort of falls apart if open strings are used).
When choosing the letter name to call each degree of a scale, you may wonder what to do when a given note can go by two names, for example D# and Eb. The way you know what to choose is that each degree of a scale has a different letter name. So for the A major scale (discussed below), you would not say it is A, B, Db, D, E, Gb, G#, A even though these notes would produce the same sound.
A major scale is obtained by following the pattern W-W-H-W-W-W-H (where W is whole step and H is half step). Consider a scale starting on A (a key heavily used in rock). The notes in the scale then will be A to B (a whole step), B to C# (a whole step), C# to D (a half step), D to E (a whole step), E to F# (a whole step), F# to G# (a whole step) and finally G# to A (a half step). The major scale always runs the entire octave. Another example of a major scale is the E major scale (again, a key used heavily in rock). Here the sequence is E, F#, G#, A, B, C#, D#, E.
Major scales have a happy sound. However, they are pretty dull and I’ve recently heard them mentioned as cartoon-like in sound. In any event, they’re very important.
Well, life is never easy and the first case comes here with minor scales. There are three main kind of minor scales and all are used pretty heavily so I better spell them out. The other important aspect of the minor scale is they for the basis of the pentatonic scale which is used (okay, overused) in rock and blues, but is sure sounds really good. But more on that one a little later.
Minor scales have a sad sound. And since there are several flavors of them, they aren’t nearly so dull. Even if playing only one kind of minor scale, they end up sounding more interesting than major scales (some kind of human perception thing).
The natural minor has the pattern of W-H-W-W-H-W-W. For example, the A natural minor scale is A, B, C, D, E, F, G, A. For the E natural minor scale, it is E, F#, G, A, B, C, D, E.
The harmonic minor scale has the pattern of W-H-W-W-H-m3-H. The m3 represents 1 and ½ steps (which happens to a be a minor third is music terms). The minor third is easiest to understand when you consider the first and third degrees of a minor scale. For example, consider A natural (or harmonic) minor scales. The distance between A (the first degree of the scale) and the third degree of the scale C is 1 and ½ steps and thus called a minor third. For the A harmonic minor scale you have A, B, C, D, E, F, G#, A. Note this makes the harmonic minor and major scales differ by only a single note (for the key of A, it is the C or C#). You might consider this in terms of being able to move from a major to minor of the same scale in playing.
This is kind of funky because up till now, the notes of above scales are the same whether the scale is being played ascending or descending. Not so with this scale. When playing the scale in an upward direction, the pattern is W-H-W-W-W-W-H. When playing the scale downwards, it is changed to W-H-W-W-H-W-W. Consider the A melodic minor scale. It is A, B, C, D, E, F#, G#, A going up and then going down it is A, G, F, E, D, C, B, A. The descending pattern is the same as the natural minor. This scale is good to sort of “mix things up”.
Two other scales deserve mention. The first is the chromatic scale. This is nothing more than playing every adjacent note between the octaves.
The other important scale is the blues scale. It has the pattern of m3-H-H-H-m3-W. When playing on the guitar, its pattern is very easy under the fingers and sounds really good.
Tons of other scales exist, pentatonic, whole tone, modes to name a few. But that’ll have to wait on Music Theory 201.
Every guitar player should learn to be able to play all the scales at a minimum starting on the low E string of a guitar. They help enormously in being able to solo. Even if you are a rhythm guitar player or power chord player, understanding how to play major and minor scales will enable you to interject a few notes between rhythm chords or power chords to mix things up and make things sound more interesting.
I had to look around for a good definition of a chord. What I found is that a chord is the simultaneous playing of three or more pitches. So, it is possible to consider the tones A, A# and B all played together a chord. But for our discussion, we’ll only consider chords that are separated by thirds. What is a third? A third are two notes within a given scale (major or minor) separated by a single key letter name. For example, consider the key of A major. A to C# is a third. B to D is a third, C# to E is a third, D to F# is a third, E to G# is a third and F# to A is a third. You’ll notice that the distance between each of these thirds is not always the same. For example, A to C# is four half steps. This is called a major third (M3). B to D is only three half steps. This is called a minor third (m3 as described above in minor scales).
A major chord is formed by constructing a major third and a minor third. For example, an A major chord would be A-C#-E. The A-C# is a major third, and C# to E is a minor third. Consider an E major chord. It is E-G#-B, again the major third, minor third.
A minor chord is formed by constructing a minor third and a major third (just the opposite of the major). For example, an A minor chord is A-C-E. A-C is a minor third (three half steps) and C-E is major third (four half steps).
Laugh….There are so many different kinds of chords as to probably take many pages to describe. For example, diminished, augmented, suspended, 7th, 11th, 13th. The only two I’ll describe a bit are the diminished (since it will play into the a chord progression discussion later) and the 7th chord which sounds really good and is used heavily in rock because it helps in was is called resovling.
A diminished chord is one in which the pattern is minor third and minor third. For example, an A diminished chord is A-C-Eb. Notice something strange here…Eb is NOT in the key of either A major or A minor. Again, we’ll get to this a little later when talking about chord progressions.
The ever famous 7th chord adds and additional third to either the major or minor chord for a total of four concurrent tones being played. Just add the 7th degree of the scale. For example, for A major, it is A-C#-E-G#. There are two kinds of 7th chords. A major and a minor. The example just given is a major 7th because the pattern is M3-m3-M3. The minor 7th is M3-m3-m3. The minor 7th is the one more typically used. For example, play a E minor 7th chord and then play and A major chord. Sounds pretty good huh? We’ll go into why later (but to give you a hint, it has to do with what notes are in the major scale).
The top note of the major an minor chords can be left off and still maintain the “feel” of major and minor. Many times, what is done is to play octaves with the third. For example, A-C#-A. This will still sound major even though you’ve left off the E. Try the A minor and replace the E with the next octave A. Still sounds minor. Sometimes this is useful in “cheating” in forming chords.
Chord progressions are what make music sound interesting from a tonal perspective. Note that it very possible to have an interesting song that never leaves a given chord, but the interest has to be achieved thru rhythm or melodies on top of the chord (or lots of drugs).
The most used chord progression in rock is the I-IV-V progression. The I means the first degree of a scale, the IV means the fourth degree of a the scale and V means the fifth degree of the scale. For example, for the key of A major, the I (root or first degree) is the A major chord. The IV is the D major chord and V is the E major chord. Why are the IV and V major chords? It has to do with the notes in the I of the key. For example, consider A major. The scale is A, B, C#, D, E, F#, G#, A. To form the I, the notes are A-C#-E as previously indicated.
For the IV (or for that matter, any degree of the A major scale you want to start on, you must select notes that are in that A major scale). Thus, for the IV, you start on D (as it is the fourth degree of the scale) and then you select thirds starting at D (remember, that’s the definition of a chord). So, the third from D is F# and a third from the F# is A (while keeping the notes in the original A major scale). Looking at the quality of third you see it is the M3-m3 and thus a major chord.
Now, look at the V chord. For the A major scale, this starts on E (the fifth degree of the scale). Going up a third is G# and then another third is B. Again, this forms the M3-m3 pattern and is thus a major chord.
This pattern holds for any major key in that the I, IV and V are always majors. Before looking at the other degrees of the scale, lets talk about the ever famous V7 chord and why it needs to be a minor seventh. Can you guess? Consider the thirds for the V7 chord in the key of A major. Start again on the E (the fifth degree of the A major scale), then G# then B and finally a third above B (and using the notes in the A major scale) will be D. Look at the quality of the thirds. E to G# is a major third (M3), G# to B is a minor third (m3) and then B to D is again a minor third (m3). M3-m3-m3 is the pattern for a minor 7th so that’s why playing a minor V7 is the correct thing to do and minor V7 to I is a hugely used way to resolve in chord progressions.
Although the I-IV-V is probably the number one progression used in rock, chords from other degrees of the scale can be used (again to make things interesting). Consider the second degree of the scale. In the key of A major, this will be a B. Starting with B, go up a third (and still using only the tones that exist in the A major scale) and it is D and then up by a third again is F#. The pattern here is m3-M3 and thus the chord that is formed is a minor chord. The third degree will be C#, E and G#. Again the m3-M3 and so a minor chord. The sixth the degree of the A major scale is F# and thus the chord is F#, A, C# so a m3-M3 and thus a minor chord. Now for the fun one. The seveth degree of the scale for A major is G#. Going up a third gets B and then up a third again gets D. This is a m3-m3. What’s this? Neither major or minor but rather the diminished.
Failing to play the appropriate major, minor or diminished chord within a given key isn’t wrong, but just sounds kind of weird. It works in jazz or contemporary classical music but not so well in rock. To be kind of uppity about it, rock and roll music listeners really aren’t that sophisticated.
Upper and lower case are used to indicate major/minor when the degree of scales are used. For example, I-ii-iii-IV-V-vi-vo –I. The degree means diminished.
The chord progressions discussed above apply to the major scale. But wait, there’s minor scales too. And in fact, three flavors of them. Guess what, this part is left as an exercise for the reader but I’ll help you out with the natural minor. You should end up with i-iio-III-iv-v-VI-VII-I.