The Basic Basics

[ashcatlt]

I've had a few people (some of whom are in my band) asking me about music theory lately. How can you tell what Key a given piece of music is in? How can you tell what's Major or Minor? What Chord goes in this Key? This information exists elsewhere on the net, but I'm too lazy to google for it, so I'm going to attempt to illustrate the basics as I understand them. It's eight pages in OpenOffice Writer, so I'm going to break it up into separate posts.

It may be remedial for some, but I hope it can help somebody.

[ashcatlt]

Let's start by looking at a piano keyboard. What's that got to do with guitar? Well, we're not talking about guitar right now. We're talking basic music theory, which is independent of the instrument upon which it's played. The piano keyboard illustrates it much more graphically than a guitar neck. Finding specific notes on the guitar will actually be easier once we've gone through this. Trust me.

Most everybody is aware that the piano keyboard has both white and black keys.



The white keys are called “natural” notes, and are given letter names: A B C D E F G. That's 7 notes. From there they repeat. The eighth note will be A, from whence we get the term “octave”. (Doesn't exactly match the image, but you get the point.)

The black keys are “accidental” notes, and are named after their adjacent white keys followed by either a # (sharp) or b (flat – you've seen the actual symbol, small “b” is the way we type it on the web). Each of these black keys actually has two names. You can name it after the white key to the left - in which case it will be called sharp - or after the white key to the right – and it will be flat. For example, the black key between C and D can be called either C# or Db. Which one do we use? You'll have to wait for that.

Less commonly known, but fairly obvious when we actually look at the piano, is that not all pairs of white keys have black keys between them. There are “gaps”, and they seem to come in a pattern: two black keys then three black keys all the way up the keyboard. This pattern repeats with the letter names. The white key to the left of any set of two blacks is always a C. From there we can find that there is never a black key between B and C, nor between E and F. Ever. This is very important to remember so I want you to repeat it.

B and C, E and F.
B and C, E and F.
B and C, E and F.

Got it? Repeat it some more.

Sometimes, in fact, we have to call B by its other name – Cb, or call a C a B#. Likewise F is sometimes E#, and E is sometimes Fb. Why? Wait a while.

So we've got 7 unique natural notes, and 5 unique accidentals. That's a total of 12 unique notes in every repetition, or octave. If we play all twelve of these notes in order it wouldn't really sound particularly musical, but we would call it the Chromatic Scale. The distance - or interval – between any two adjacent notes in the Chromatic Scale is known as a Half Step or Semitone. A Whole Step or Whole Tone is an interval of two notes on the Chromatic Scale. B to C is a Semitone. C to D is a Whole Tone.

[ashcatlt]

As I said, the Chromatic Scale isn't particularly musical. Most modern Western music uses notes in one of a number of subsets of this scale know as Keys. These Keys consist of exactly 7 notes from the Chromatic Scale. If you're paying attention you will realize that we also happen to have 7 natural notes. Is that a coincidence?

The notes in any given Key are not chosen at random, but rather for a very good reason. They always fall into a specific pattern of Whole Step and Half Step intervals, and yes this pattern is exactly the same as the white keys on the keyboard. Now can you see why I started off talking about a piano?

If we start playing on a C, and play each white key up (to the right) in turn until we reach the next C, we will hear that familiar “Do Re Mi...” thing, and will have played the scale which corresponds to the Key of C Major. C Major is all the natural notes, no accidentals. Ever.

Let's write that out:
C D E F G A B C

Yes, I repeated that C. Let's take a look at the intervals here. From C to D is a whole step (there's a black key between). D to E is a whole step. You remember (don't you?) that there is no black key between E and F, so that interval is a half step. F to G whole. G to A whole. A to B whole. Then there's no black key so B to C is a half again.

I'll write it out again, but this time with a dash (-) between the notes which are a semitone apart. Whole tones just get a space:
C D E-F G A B-C

The pattern we've described here goes...
W W H W W W H
...and is true of every major scale. We can start on any note we'd like, pick notes to fit this pattern, and we've got a major key. That pattern is pretty easy to remember, but it can be a lot simpler if we just remember the two exceptions, rather than the whole sequence of seven intervals.

So let's abstract this a bit. Rather than the specific note names, we're going to use Roman numerals to denote the position in the scale of each note:
I II III-IV V VI VII-VIII

From this we see that there is a semitone between the third and the fourth scale tone, and between the seventh and the eighth (octave).

This is very important to remember so I want you to repeat it.

Third and Fourth, Seventh and Eighth.
Third and Fourth, Seventh and Eighth.
Third and Fourth, Seventh and Eighth.

Got it? Repeat it some more.

There is a mathematical logic to this pattern, but we're not going to get into it here. For now, just repeat and remember.

[ashcatlt]

If you were to go through and apply this pattern and write out the scale starting on each of the 12 notes in the Chromatic Scale (and if you really want to learn this stuff you will, but wait a couple minutes) you would find that each set of notes is completely unique – there is always a specfic combination of naturals and accidentals which is not repeated in any other Major Key. Not to get all mathy, but this is exactly because 12 is not evenly divisible by 7.

In fact, in traditional written music (you know, on that “Every Good Boy...” staff thing) when you look all the way over to the left you will often see some number of sharps or flats in what is called the Key Signature. This defines the Key of the piece, and tells you which notes should be sharp or flat or natural. (Only one of the notes is marked in the Key Signature, but all notes with that name should be played the same. There's two Fs on treble staff – the first space from the bottom, and the top line – but even though you'll only see the # symbol on the top line, you will play any F as F#)

Once you get all of this stuff down, you'll be able to simply count the #s or bs and know exactly what Key it is in, and also which notes those #s or bs belong to, without even having to look at where they sit. One # in the key signature means the Key is G Major and the sharped note is F#. Three #s in is A Major, and the it has F#, C#, and G#. Don't believe me? Let's prove it.

Start with G. Whole step to A. Whole step to B. A Half Step from there gets us to C. Whole Step D. Whole E. There's no black key between E and F, so to make a Whole Step from here we go to the black key above F – F#/Gb. And now we get to answer one of those hanging questions from earlier. Why should we choose to call this F# rather than Gb? Well, what would happen if we put a b on the G space in the Key Signature? We'd never get to play a G natural without an incidental mark, and since we're likely to play a whole lot of Gs, that would be too much messing around. In any given Key we can only have one note with a given letter name. Also, we have to use all the letters. If we call it Gb, we don't have any note named F anything. Poor F. Then we have a Half Step to the octave G.

So:
G A B-C D E F#-G

We'll get to the A Major, but first let's do the Key with 2 #s. I choose D.
D E F#-G A B C#-D

And now we can do A:
A B C#-D E F# G#-A

Now, can you tell me what Key will have the fourth # in it? Well, if you've been paying attention you may have noticed a pattern emerging here. We started with C – all naturals. The first sharp was found in G which is the V (fifth, or dominant) tone in the key of C. D is the V of G, and A is the V of D. So the next must be E, right? This is what we call the Circle of Fifths.

But which note will be sharped in this key of E? Well, you may have noticed that each new key keeps the sharps from the previous, and adds a new one. That new one is always the VII (seventh, or subtonic) note of the scale. So it must be D#:
E F# G#-A B C# D#-E

Keep going around the Circle of Fifths and we get:
B with 5 sharps
F# with 6, which answers that other hanging question:
F# G# A#-B C# D# E#-F#
and then C# which has all 7 notes sharped.

[ashcatlt]

Now we haven't talked about flats yet have we? Well this is where they come in.

See, if we want to keep going up the Circle of Fifths, we will go to the V of C# Major, which is G#. If we write that out, we get:
G# A# B#-C# D# E# F##-G#
Note the F##. That ain't no typo, it's a double-sharped F. But it's ugly and difficult to say. It's also the reason I told you to wait before you went writing out all the Keys. What happens, though, if we call that I note (the root, or tonic) by its other name – Ab?

Ab Major:
Ab Bb C-Db Eb F G-Ab
That's a lot nicer, no?

But that's 4 flats. What's the first Key with a flat in it, and what is that flatted note? Recall that we started the Circle of Fifths on C, and went through to C#. For it to be an actual circle, though, it would need to come back around to C. Eventually it does, but let's just go backwards. For which Key will the note C be the V? You could go through and apply our scale pattern backwards from C – down a Whole Step, Half Step, Whole Step, Whole Step – or if you're really paying attention you could look and see that B is the V of the E Major scale, and C is a semitone above B, so we must be looking at...

F Major:
F G A-Bb C D E-F

And here you'll notice that F is the IV of the C scale, which makes this backward navigation a bit easier.
Bb has 2 flats
Eb has 3
Ab has 4
Db has 5
Gb has 6
and Cb has all 7 flatted, which only makes sense, right? It's also the key of B, which has 5 sharps and is therefore a little easier to remember. Let's not talk about Cb.

So now we've got all 12 of the Major keys.

[ashcatlt]

But that ain't all the keys in the world, is it? You've heard of Minor keys too, right? What's the deal with those? Well, the Minor scale is really just the Major scale started from a different note. Umm... that sounds weird. Let's take the abstract Major scale:
I II III-IV V VI VII-VIII

Keep the intervals in the same place, but change the numbers so that the I is where the VI is:
III IV V-VI VII I II-III

Then we can slide the thing over to put the I at the beginning and we have what looks like a new pattern:
I II-III IV V-VI VII VIII

It's not really a new pattern, just the same old pattern started in a different place, but it's different enough and important enough that you should remember it. In a Minor Key there is a Semitone between the second and third, and between the fifth and sixth.

Second and Third, Fifth and Sixth
Second and Third, Fifth and Sixth
Second and Third, Fifth and Sixth

Got it? Repeat it again.

So now you have caught me in a lie. Remember when I said that if you see a single # in the Key Signature then it must be the Key of G Major? Yeah, well, it could also be E Minor:
E F#-G A B-C D E

Every Major Key has a Minor Key which shares the exact same set of notes. This is called the Relative Minor. E is the relative minor of G. The relative minor of any major key starts on the VI note of that major key. The Major Key to which any Minor is relative is always the III of that Minor Key.

There's another way to make a Minor Key, though, and it's fairly important as well, so here it is:
Start with the Major Key with the same root.
Flat (lower by one semitone) the III, VI, and VII.
Done.

Let's use E to illustrate.

E Major: E F# G#-A B C# D#-E
The III is G#. Lower that by one semitone (flat it) and you get G. The VI is C#. Flat that to C. Flat the D# (VII) to D and you're left with E Minor:
E F#-G A B-C D E (same as above)

Third, Sixth, and Seventh
Third, Sixth, and Seventh
Third, Sixth, and Seventh

Got it?


Now you can go through and write out all 12 Minor Keys and identify them as Relative to the Major Keys. Great.

[ashcatlt]

Now what about Chords? How do we know which Chord fits in which Key?

First, what is a chord? It's a set of two or more notes (usually) played simultaneously. For reasons having to do with wave math (which we won't get into here) some combinations of notes sound more satisfying to our brains than others when heard simultaneously. Some sets of notes are more harmonious, and some are more discordant.

The most harmonious of combinations (other than a pure unison – the same note in the same octave doubled) is the octave. This should be pretty obvious. Both notes have the same name, so they must sound good together, right? The next most harmonious is the fifth. That is, playing the I and the V of the scale together. This is pure and powerful and strong. A good foundation. It's the “power chord” that we hear all over rock and roll. It works out to where this is the chord which comes out clearest when played through distortion (again for reasons related to wave math) and for that reason genres like Punk Rock, and especially Metal rely on the “power chord” almost entirely.

Like I said, it's a good foundation, but doesn't offer much in the way of emotional content. We need at least one more note for that. We need to find the next most harmonious note. Well, that's going to be one of the Thirds. In both the Major and Minor scale the V is exactly the same distance from the I – a total of seven Semitones. But if you look at the IIIs, you'll see that they're different. The Major Scale has the III at four Semitones above the root, while in the Minor it's only three. Either one harmonizes with the I-V combination just fine. There's a subtle difference in the tonality and emotional content here, though. The Major Third feels upbeat, happy, reassuring. The Minor Third feels a bit darker, more melancholy.

If you start to add more than three notes, things start to get crowded, and discord starts to creep in. For that reason, the generally accepted most basic Chord in western music is this group of three notes – called a triad. A triad can be either Major or Minor depending on that Third. The Chord is named after the scale with the same root in which all three notes fit.

The C Major chord (usually written as simply C, the Major is implied if not otherwise noted) is spelled:
C E G

The A Minor chord (Am, Minor is never implied):
A C E

But remember there was two different ways to make a Minor Key? There's also another way to make a Minor Chord:

Take the I III and V from the Major scale named after the root and that's a Major Chord.
Take those same three notes, and then flat the III, and it's now a Minor Chord.

[ashcatlt]

Okay, but how do we know what Chords go in which Key? Well, in order for a Chord to fit a specific Key all of its notes must also fit in that Key. The chord is named Major or Minor after its own scale, but all the notes must fit the Key of the piece in which we're playing.

Can you play an Am Chord in the Key of C Major? We know that C Major is only natural notes, and there's nothing but natural notes in the Am, so we're cool. Can't play A in C Major, though, cause of that C# note.

Now here's how we can figure out exactly which chords go in a given key. We'll just write the scale three times on top of each other, starting each one from a Chord tone.

Let's do C:
C D E F G A B
E F G A B C D
G A B C D E F

Then we read downward to get the notes in each Chord, and then compare and calculate and figure out whether each of these is Major or Minor.

We'll get into problems with that B, though. B, D, and F don't fit into either the B Major or B Minor Keys. The V of B (the same in both Major and Minor, remember?) is F#. The F here is one Semitone flat of that. In fact, if we compare it to the B Major scale we see that both the III and V are flatted here. That's what we call a Diminished Chord – written as Bdim, or B^o. It's quite discordant, and rarely used. It's scary and uncomfortable, and demands that we get back to our nice safe home at the I.

I'm not going through all the different scales to illustrate which of these Chords is Major or Minor. I'll just note them below:
C D E F G A B
E F G A B C D
G A B C D E F
M m m M M m o

That doesn't really line up so well there, but you get the gist. The pattern for a Major Key is
M m m M M m o. The VII is always Diminished, and the I, IV and V are always Major. All the rest are Minor.

VII dim, I, IV, V Major
VII dim, I, IV, V Major
VII dim, I, IV, V Major

If we do this for A Minor:
A B C D E F G
C D E F G A B
E F G A B C D
m o M m m M M

II dim, I, IV, V Minor
II dim, I, IV, V Minor
II dim, I, IV, V Minor

In fact, when we're talking about chords, we often use roman numerals with capitals as Major chords, and lowercase as Minor. Still have to note that diminished chord, though:

Major:
I ii iii IV V vi vii^o
Minor:
i ii^o III iv v VI VII

From the above you may have noticed that the IV and V always “follow” the I chord. If the Key is Major, then the I will be Major and so will the IV and V. In the Minor Key, they're all Minor. This is pretty convenient when you find yourself playing most Country, Blues, or Rock music. They rely almost entirely on some combination of the I IV V chords. As long as you know whether one of these should be Major or Minor, you know about all three.

Eventually you'll find that you can tell the Key given any two Chords, even if you're not sure what “number” these are supposed to be.

[JohnH]

Outstanding work Ash! +1 every day for a week!. This will definately help me.
with thanks
John

[ozboomer]

Excellent presentation... and will be very useful, methinks.

Whilst there are literally hundreds of web sites that deal with "the circle", in terms of answering the basic question of "What key is it in?", a web site that uses "the circle" to help answer that question is "The Interactive Circle of 5ths". It also shows a handful of other useful ways to look at "the circle".

True, there are tricks like, if you have 2 adjacent major chords they will likely be the IV and V (Major key) or VII and VII (Minor key), as explained by Ash... but! the key may be modulating (changing) mid-song (or even mid-measure)... but that's beyond the scope of this thread...

Well-done, to get some more theory out there... as even basic basics can be most helpful to those who have found themselves in a rut.. and help them escape to make more musical discoveries

[cynical1]

A very good graphic on the Circle of Fifths is here:


Click me for the Big Picture!

And great post, Ash. +1.

And congrats on busting 2000 posts.

Happy Trails

Cynical One

[newey]

Great job, Ash! I'm sure I'll be referring back to this from time to time. I've been studying this stuff in my lessons for a while now, but your explanation is better than those in the books.

[4real]

Another +1 from me Ash, a good overview.

I am sure that for many such things might make one's eyes glaze over (I personally love 'theory', curious by nature perhaps).

I think it is important for many that I have discussed these kinds of topics here, that these kinds of things are not 'prescriptive' but are indicative of western music tradition and function and even where some elements seem to ring untrue or overly complicated in a style of music, this kind of language can reveal deeper meanings to what is going on.

One common fear that I've run across is that people may think that by learning something like this, playing scales and such...that this will become the vocabulary and you will 'loose soul' or something in the process. I really don't see this as true if you approach it with the right attitude and don't think that because you know this kind of thing, that you don't appreciate a basic song or chord progression.

I found a similar thing when much younger and practised scales and melodic sequences quite a bit with strict alternate picking and 'correct posture' and all that. I wasn't necessarily going to play 'scales' as some might do under such a regime, but it did give me a wonderful knowledge of the fretboard, great left hand finger independence and control, sharpened up the timing (if used with a metronome as well as injecting feel in various levels of swing and such) and pick control.

The end result of this kind of work is that you can put your fingers where they need to go, because they have been there before or something similar...and that they 'know' where to find other notes within the tonality.

A similar thing with theory and playing this stuff (it is important not to just read this kind of information, but to play and hear it...play all the chords that are generated within a key, find the common sequences, learn it in all the keys)...it can really help when playing with others, learning a tune, or even writing something if you have a good idea of what to expect. Where things are not as might be expected, then that tends to stick out and although might not fit within the ' basic theoretical model' shown here, the knowledge will help and give an even greater appreciation of how people have manipulated things effectively outside the norm.

Anyway, a great resource +1