Improvising. Part 1: Understanding Keys, Scales And Chords

Part One in my series on Improvising on the guitar deals with the structure and uses of a key, as well and some basic pointers about music theory you will find helpful throughout the course.

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Keys

People often get in a muddle about keys, especially those that do not read sheet music. It would be silly to dwell on them in a series focusing on improvisation, but given that they are, essentially, the grounds upon which any song you are going to improvise over is written, some instruction is probably required.

Okay, a song is essentially a collection of notes. These notes relate to each other to form harmony, which is where the music comes from. A key is, essentially, which notes you use. These are the ones that the melody (be it sung of played) uses and the ones that the chords are made up of.

There are two kinds of key: major and minor. Major ones sound happy and minor ones sad, although much of the emotion in a piece comes from composition and not choice of key alone. Let us look at a few examples (NB a note with # after it is raised by one. One with b next to it is lowered one semitone. And a semitone is one fret i.e., the first fret on the 6th string is one semitone lower than the second fret on the 6th string)

Let us consider some examples, just so you know what I'm getting at:

C major's notes are

C, D, E, F, G, A, B
D major's notes are
D, E, F#, G, A, B, C#
F# minor's notes are
D, E, F#, G#, A, B, C#
Simple. I could fill an article on how a key is formed but for now it will do to understand their basic function.

Notice, also, how the keys are set out. The note the key is named after, which is called the root note or just the root comes first. We give each note a number, normally done in roman numerals, so the key note is I (one) and the second note is II (two) and so on. See below

C major's notes are

C D E F G A B I II III IV V VI VII 1st 2nd 3rd 4th 5th 6th 7th
These numbers are also used to talk about the chords, so chord V in C major would be G. Chord III in D major would be F#.

A Quick Note About Scales

There's going to be lesson after lesson on scales, but all you need to know now is that If you play a scale, you play the notes of that key in order, most usually ascending then descending.

Chords

Chords are a real stickler, but basically govern what you play when improvising and so it's best to tackle them now. Let's look at them as simply as possible:

  • A chord is a collection of notes, played simultaneously, that normally have some harmony and so sound nice.

  • They are made of the first, third and fifth notes of their root. That isn't the root of the key, but the root of the chord, i.e. the note the chord is named after. So C is C-E-G.

  • There are tow kinds of chords, major and minor. Which one you use depends on what key you are. This is because, as mentioned before, you have to use the notes of the key when writing the song (well, I say have to... but lets get to that in due course).

    So, lets say an A chord is being played in the key of C major. A major's key has a C# in it, making in A-C#-E. Yet the key of C major has no C# in it. Crisis! Or not, as the case may be. One simply plays an A minor, flattening the third (C# becomes C) to fit the key signature. This new chord is called an A minor.

    And why? Well there's two ways of looking at this. One is simply that, when you flatten the 3rd of and chord, it becomes a minor chord. The other is that, in the key of A minor, chord one (A minor) is A-C-E.

    Identifying A Key

    It helps a lot to know what key you are in. How can you work this out? Here are a number of strategies:

  • If all/most of the chord patterns start on a particular chord, then that is a likely candidate for the key.

  • If one chord is used a lot, then that is another likely candidate.

  • If, on numerous occasions (particularly at the end of a section) the penultimate chord goes to the final one as so: G-C, or E-A, B-G (notice the common difference between them, i.e. there are two notes in-between them) then the final chord (C, A, G) is probably it.

    The Hard Way

    Write out all the chords that are used in it, ignoring any that are only used very rarely or that appear to be dissonant (that is, they do not fit with the music), including whether they be major or minor. Compare them to this

    Chord Number: 1 2 3 4 5 6 7 Tonality: maj min min maj maj min (diminished, but ignore this).

    and see what pattern most likely fits this one.

    eg.

    We have

    G major, D major, B minor, A major, in a chord progression, These all fit in if we have D as chord one with the chart above, so it is likely in D major.

    If, however, a chord progression appears more minor in its tonality, it is likely in a minor key. Identify its key as above, but then you will have to find the relative minor. A relative minor is the minor key which shares its notes with a major key, for instance, A minor shares its key with C major; simply lower 3 semitones from the major key to find its relative minor.

    Hopefully that has cleared some stuff up for you all. I realise there was zero on improvising in this particular episode, however next time I hope to at least introduce some basic scales and ideas that will, eventually lead towards some simple improvisation exercises.

  • 64 comments sorted by best / new / date

      Lensver
      I was always confused when someone started blabbering about keys, modes and stuff. I wanted to learn that thing such a long time ago - thank you for putting it this simple, a few more reads and it should be clear. Thanks again, great article
      jeffbirt
      It is good that you explain the numbering of the notes in a key, but that information can be (often)used to detect the key in which a piece is written. (WARNING: my theory was all learned on piano, but it applies here. For example, songs written in major keys will typically use the root chord, the major chord of the IV note in the scale, the major chord of the V note in the scale (often a seventh), and the minor chord of the III note. For example, if you know the chords in a song are C,F,G7, and Em, you can determine that the key is C because C is the root, F is the IV, G is the V, and E is the III. Now admittedly, this requires a little detective work and knowledge of the notes in a scale, but it is very useful. Its real utility is in writing. Say you want to write in the aforementioned key of Dmajor. The scale is D,E,F#,G,A,B,C#. So, the chords to use would be D(the root), G(the IV), A or A7(the V), and F#m (the III). Obviously, you are not limited to these chords, but the pattern is I Major, II minor, III minor, IV major, V major, VI minor. So if you wanted to add another chord to your song based on the II, it would be Em (still talking about the key of D). This was a major eye opener for me when my instructor told me this. I hope it helps some of you as well. (I won't pretend for a second that I know if this applies to anything other than major keys. Also, it is always allowable to deviate from your key and throw in an accidental, so user beware.)
      zhille
      Good article, pretty basic, you can get that anywhrere, but I think you have explained it in human terms...I had the luck to figure that out almost by myself, 5 years ago, when I started playing. I often find myself starting to explain things to people and they just look at me blank...and then I remember that beginners want this kind of explanation. I solely think you should cover a little more ground. But it will surely be covered in next lessons. Good job.
      concept:one
      Aye aye, didnt want to swamp people with too many facts. Theory can be bewildering at first.
      zhille
      bobsyouraunt wrote: I was never quite sure on this one, but isnt what you say a 'minor', actually the aeolian mode rather than an actualy minor scale. Aren't the minor scales the harmonic minor and melodic minor (that changes up and down)???? correct me if im wrong, i dont really know myself
      We divide minors into NATURAL, HARMONIC and MELODIC(ascending, changes to harmonic descending). the natural minor scale is the same as the aeolian mode, so you can call it whatever you prefer...I personally find it a bit unusual when someone says he's playing in ionian(major) or aeolian(minor). This is stupid..go get theory books Berklee's harmony is one thing everyone must have, and it's easy to understand, you only need to know to read notes. And the first tome teaches you just that! GO GET IT! It's cheap...for all the amount of knowledge you will gain
      GodofCheesecake
      concept:one wrote: Aye aye, didnt want to swamp people with too many facts. Theory can be bewildering at first.
      That it can
      battleguard
      They are made of the first, third and fifth notes of their root. That isnt the root of the key, but the root of the chord, i.e. the note the chord is named after. So C is C-E-G.
      Eh.. not entirely true.. it works for beginners, but its a little off.. major and minor triads are constructed using that method.. but not other chords such as sus2 dim etc..
      MetallicaNRoses
      yeah it annoys me just a bit that you say things that aren't entirely true for the sake of the beginners, but i can understand why you would do it. good article.
      dickie_kak
      Good for beginners. But I really think Keys are more complex than what you described here. And in your defence, you don't really have enough room to describe it thoroughly enough.
      ihaveatail
      this is great if you really don't know anything but some of it will confuse beginners later on. i suggest you point that out. too much of that and it could be a setback.
      gino23
      Sometimes , beginners are slow learners and sometimes they are fast learners. If a beginner really wants to play guitar wonderfully , they study and study some chords and some chords with bars and I think Keys as well to learn them. Some beginners just want to learn by themselves. Its hard to learn to play a guitar by yourself sometimes but, Having someone to teach you will be easier. They teach you about guitar basics and also keys. I think all the fast learners can understand this nice article. VERY VERY VERY NICE ARTICLE!!!!
      bobsyouraunt
      Fair enough, i use it too when soloing over minor stuff, but it never made sense why everyone called it the minor scale when it isnt, but i guess it kind of is really. Ahh, the joy of learning about modes. Oh well, nice article. Keep up the good work.
      warlockking
      great article for beginners, i know all of it, but i'll be reading the next one. doesn't have much to do with improvisation, but a good article.
      Kurniawan4000
      I'm fortunate to have found this article while browsing around. It is simple enough to understand! 10*
      ads062194
      wow, very nice article. i wish i would have read this a long time ago. i knew most of it but it definetely is a great article.
      the_bi99man
      sTx wrote: These numbers are also used to talk about the chords, so chord V in C major would be G. Chord III in D major would be F#. Won't it be F?
      it would be in the key of D minor . Anyway. I'm still very confused about something. I hate just memorizing things and I prefer to be taught to do something by being taught how to figure it out on my own, then do it myself. That's how I learned to construct chords, and find and label the notes in a specific scale. I'm still confused about keys, though, because I can't find any lessons on them that doesn't basically go, "these are the chords in c major -memorize them... these are the chords in d major -memorize them..." and so on. I found a pattern that I think is correct... To find the chords in a given key (we'll go with C Major), you take the notes of the key's scale (c major -C,D,E,F,G,A,B) and the then the first, fourth, and fifth of those notes (c,f,g) are major scales, the second, third, and sixth of those notes (d,e,a) are minors, and the last one is dimished. Someone who knows, please tell me if I'm correct on this one. Also, I understand that when using that given key, the relative scale of that key (C Major scale in the key of C Major) would be a good one to use to solo over it. Am I right on that one? If so, how would I go about finding the chords in a minor scale?
      PoopChute
      ok i still dont know how to find out what key a song is in or even my own lil improvisations EG: D 0h2p0 3 2 2 A 2 3 2 2s5 5 3 2 2h3p2 2 E 0 5 3 3h5p3 3 2h3p2 0 notes used: A B C D E F F# G So what key is it in what scale? And how do you know?
      PoopChute
      Fuckin Goddamnit D---0h2p0-----3-2-----2 A--2-----3-2-----2s5-5-3-2-2h3p2-----2 E-0-----5-3-3h5p3-3-2-2h3p2-2-0
      PoopChute
      D-----0h2p0-----3-2 A---2-----3-2-----2s5 E-o----- A-5-3-2-2h3p2 E-----5-3-3h5p3-3-2-2h3p2---E5
      villageidiot14
      dude, this is so confusing, where should i be looking for a beginner on scales/keys because this, this is not making any sense to me. Where do i start so that i can come back to this and it will?
      concept:one
      Modes will come. I dread the day when I have to try and put that in language anyone could understand. Bah.
      concept:one
      That is correct, but the aeolian mode is a minor mode, or rather the minor mode, in that it is the mode most commonly used when playing over pieces in a minor key. This issue will be approached at a later date but for now, for a beginner, it is best to view things how I have approached them.
      antareus
      Nice work. Easy to read and covers some ground. Looking forward to your next one.
      bobfett669
      Excellent introduction for beginners who are looking into music theory and chord progression
      edibledevilboy
      hope theres more on this, i pretty much know all this but without knowing how it can help me rather than me going by ear like i have done in all my time playing guitar so far
      sTx
      These numbers are also used to talk about the chords, so chord V in C major would be G. Chord III in D major would be F#.
      Won't it be F?
      concept:one
      sTx wrote: These numbers are also used to talk about the chords, so chord V in C major would be G. Chord III in D major would be F#. Won't it be F?
      No, D major's key is D, E, F#... and so on.
      kennymac99
      wow, i never realised how much of a theory noob i was lol ive been playing for over 2 years and im pretty technically proficiant, yet all this is kinda new to me! but yeah...great article! for beginners such as myself!
      hairypineapple
      When I got to the end I thought... WHERE THE F*CK IS MY IMPROVISING LESSON!? But the title "does" explain that... bring on part 2! Id say its gonna be good
      Wratheh
      I knew most of this but it was explained in a very good way, keep it up
      kaze_no_oto
      These numbers are also used to talk about the chords, so chord V in C major would be G. Chord III in D major would be F#. This part confused the hell out of me. I don't see the logic and it wasn't really explained.. Everything else was good. Anyone wants to explain that part so I can better understand, it's definately welcome - I'm just breakin into theory after about 8 years of guitar and bass.
      hengler
      In each key the steps go: WWHWWWH where W = whole tone (i.e. two frets) and H = half tone (i.e. one fret) so in D: WWHWWWH go up two frets to E so you have D - E then another two frets up from E is F#, as there's no E#/Fb note between E and F
      hengler
      Posted too early there: so that gives D - E - F# and it carries on according to the pattern at the start: D E F# G A B C the WWHWWWH pattern applies to all keys
      bobsyouraunt
      I was never quite sure on this one, but isnt what you say a 'minor', actually the aeolian mode rather than an actualy minor scale. Aren't the minor scales the harmonic minor and melodic minor (that changes up and down)???? correct me if im wrong, i dont really know myself
      Icarus Lives
      Even though I knew all this stuff and I know a few scales I'm still really lookin forward to the next few parts. This is like a step by step bullshit free guide which is what I'll need when he gets to the stuff I don't know. Brilliant article!