The Musical Genome Project

I spent the better part of my college days in the company of engineering students. It spoiled me in a lot of respects. There seemed to be no problem they couldn’t fix when it came to gadgets, cars, stereos, musical equipment. They seemed to spend their “spare time” taking things apart just to see how they worked and then chanting some sort of magic spell so that when they reassembled an object it would be better than it was before its dissection/analysis.

Human beings seem to be curious by nature. It accounts for a lot of things, I suppose. And anytime I might forget this fact I get a gentle reminder through the questions that we receive both via email and the Guitar Forums.

And it occurred to me, looking over all the questions about scales and leads and chords and melodies that I have gotten, that it’s as a good time as any to answer these as fully as possible. But in order to do that I realized that I would need to take everyone back to the beginning steps of music theory once again – to give you a more thorough introduction to it than I did last November (Theory Without Tears).

As I promised last week, these lessons will be short and (hopefully) easy to grasp. What I didn’t tell you, is that I’ve also included some “homework problems” for those of you who might want to try out your newfound knowledge. The answers to any given week’s problems will be printed the following week. In addition to these “problems,” there will also be “exercises” for you to try out (although not necessarily both on any given week). The “exercises,” unlike the problems, will not have “correct” answers. These are intended to help you explore different aspects of theory. For instance, I might give you a chord progression and ask you to submit a melody line, or a riff, or even a lead line. Likewise, I might give you a melody line and ask you to put a chord progression to it. In these exercises, I will then take the time to go over your answers in a following column (which will probably be two weeks later than the initial column, due to the logistics of things).

For those of you who are worried that this will keep me from covering other topics, rest assured that this shall not be the case. I’ve been compiling a list of topics since the day I started writing for Guitar Noise (a lot of them, as you know, are suggestions taken directly from your emails and requests) and at last check I was far from the bottom of that list! It simply means that I’m going to have to write more! So please bear with any “growing pains” that we might experience in the upcoming months! Hopefully, it will be worth it for all of us.

Building Blocks

Just like genetic scientists, we have basic units with which to build music, whether a melody, a chord or whatever. We use notes as our foundation for tonal music (and for the time being we are only going to concern ourselves with the tonal qualities of music – the rhythmic aspects of it will have to wait “˜til a later date).

According to the conventions of music theory, there are just twelve notes to deal with, each separated by what we call a half-step. This is a given fact. Now, yes, we can argue this all we want to, but it will not change how we perceive music. Some things became written in stone looooong ago. Don’t worry about the why’s for now. But do note that the half-step is very important to us because on the guitar every fret designates a half-step.

These are the 12 notes that we have. Please observe that some of the notes have more than one name:

12 notes

The note after G# (or Ab, if you prefer) will be A again. Then the cycle starts all over. If I were to tab out these notes, starting from the open low E (6th) string, it would look like this:

The notes

Now if you take a minute to think about this, you’ll understand why we tune the guitar the way we do. The fifth fret of the 6th string is the same note as the open 5th string and so on.

You might also want to take the time to realize that you now have in your possession a great tool to help you read music! We can be so sneaky some times…

In some ways, it’s easy to think that music was set up by the same people who brought us weights and measures BM (before metric). All we can do is learn it the same way we’ve learned anything – memorize it first and ask questions later. I don’t really espouse this myself, but it does work. The majority of you could probably show me how to play an Am7 chord, but I’d wager that at least a quarter of you could not tell me the notes of which it is made.

Another given we have from the powers-that-be is the composition of scales. A scale is the sequence of notes used from a specific note to the next occurrence of that same note. This sequence is usually a combination of whole-steps and half-steps. Let’s look at our notes again (and I am going to use small numbers to mark the half-steps):

Our scale

A major scale uses the following steps: root, whole-step, whole-step, half-step, whole-step, whole-step, whole-step and half-step. Utilizing this pattern, we can easily come up with the A major scale (and it’s called an A major scale because it starts out on the note of A):

A major scale

I kept the numbers in for another sneaky reason. Since you know that the notes keep on repeating themselves in an endless cycle, you can actually use this method to figure out any major scale your heart desires. Go ahead and pick a key, any key. Use that note at your “1” and then write out all the half-steps until you get to “13.” Done? Now just take the notes in your 1,3,5,6,8,10, 12 and 13 positions and voila! – instant major scale. Piece of cake, huh?

But, for your own sake, don’t get hooked on this method. Do yourself a favor and try to acclimate yourself to figuring it out note by note, step by step. When we get to discussing aspects of chord theory we use numbers that will mean totally different things and there’s no sense of adding to the confusion! After all, there are only twelve major scales to deal with (and it’s highly doubtful that you’ll ever use four of them!).

The major scale is incredibly important to us because, as we’ll see next week, so much of chord theory is based around it. In the meantime, though, let’s look at the A major scale on the fretboard:

A major scale

You might also want to realize that, if we wanted to, we could extend this scale down from the low A as well. Of course, we’d only get to the E (open 6th string), but it would give us three more notes. It’s always a good idea to extend any scales as far as you can on the fretboard. For now, though, we will content ourselves to keeping within the confines of the fifth fret on any given string.

Keys To The Kingdom

For reasons, which, again, must have seemed great at the time, the C major scale is constructed in such a way that it has no flats or sharps. Because the interval between E and F (as well as between B and C) is a half-step, this works out perfectly.

Other keys have any number of sharps or flats and, believe it or not, there’s actually a pattern to it! Look:

Pattern of sharps and flats

This is where the infamous “Circle of Fifths” comes from. If you look at these as chords instead of keys, you can see that each one is the fifth of the following chord. And since you realize that F# and Gb are the same note, the “circle” is indeed complete. A song written in a key of seven flats would be in Cb, which is B. For all intents and purposes, though, people tend to stick within this circle. I mean why would you even think about writing in a key that had more sharps (or flats) than there are notes?

Before we close with some exercises, let’s take a look at the C major scale, both in notation and in TAB:

C major scale

For the sake of convenience, I bracketed the actual C major scale and ran the scale’s “extensions” on both sides of it as far as I could go within our set parameters. This really becomes important when you’re trying to work out bass lines (yes on your guitar) as well as leads and riffs.

Someone once asked me how people go about taking a scale and making a lead or a riff out it. There are really no set rules, per se. It’s simply a matter of working with the notes you have and coming up with (a) something that fits the songs and (b) something that you like. It doesn’t have to be overly complicated. I know that this is going to be showing my age (“God, doesn’t he know any songs from this century?”), but Cat Stevens’ Wild World is a good example of what you can do with a simple scale in first position. Here’s the notation and TAB for the riffs in the chorus:

Wild World part 1
Wild World - part 2

As you can see, the first riff is just a descending C major scale. Nothing to it, right? The second riff consists of a pattern of G, A and C notes. The rhythm is slow, so even though the riff is made up of sixteenth notes it’s still very straightforward.

What I like about this particular piece is that if you have two guitars, it’s very easy to add a harmony part to the first riff. The second guitarist starts on A (second fret on the G string) (this makes two thirds of an F chord, by the way) and then continues down to the open A string. Since the following chord is a G, this second voice leads right into that note in the bass:

Wild World - part 3
Wild World - part 4
Wild World - part 5

There are, of course, plenty of leads and riffs that are based around simple scales and we will be covering quite a few in the months ahead. If you’d like to whet your appetite in the meantime, might I suggest you try Paul’s article Easy Guitar Riffs. And there’s plenty more that will be coming to Guitar Noise in the months ahead.


  1. The vast majority of music for the guitar is in the keys of C, G, D, A, E and their respective relative minors. Since we’ve already done A and C for you, write out the note of the scales for the
    • G major
    • D major
    • E major
  2. Using either notation or TAB, map out where the notes of these scales are on your fretboard. Be sure to extend your scales as far as you can in either direction using any notes found between the open strings and the fifth fret on all your strings.
    • G major
    • D major
    • E major
  3. You might want to go back and reread the first part of Scales Within Scalesfor this but I think you can do it! Write out the notes for the following scales:
    • D Natural Minor
    • D Harmonic Minor
    • B Natural Minor
    • B Harmonic Minor

As you can see, the “homework” is pretty minimal! The answers will be here next week. We’ll also show you how to build any type of chord your heart desires!

As always, please feel free to write in with any questions, comments, corrections, concerns or requests for topics to cover in future articles. Or just to say “hi.” You can reach me directly at [email protected] or just drop a note over at the Guitar Forums. So, until next week, then.


More in this series on Chord Theory