Capos, Keys, Scales and Me - Part II
I have been bouncing around various web sites, forums and bb’s looking for some answers and the best resource I could find as far as this stuff goes is musictheory.net. Although not entirely geared towards guitar, it is still a valuable site to anyone wanting to learn more about music and the theory behind it.
The first thing I am going to delve into is how you go about determining the key of a song, because once you figure out the key, the scales will follow. A capo will just change the key of a song, so obviously knowing the initial key before you change the key using a capo, will help. I found various people asking the same question: “how do I find out what key a song is in” and I found many answers, most were incorrect. Most often the first answer was, find the first and last chord of the song and that will be the key of the song. Obviously this is not entirely true, BUT I would say it is true for 80% of the songs out there. The main problem I see with this approach is there could be key changes during the song, and you would never realize it. If you get called up to jam out a song during one of your friends local shows in front of hundreds of people, and the song changes keys right before your big solo……… you would look like an idiot! Believe me; I have faked my way through many solos, but once the key starts changing and you don’t know where you are, you will be in trouble. Hopefully after reading this, you and I will be able to determine a songs key on the fly just by knowing the chords or listening to it.
I am going to try and summarize musictheory.net’s key signature lesson at the same time applying it to the guitar. I highly recommend checking out the lessons on musictheory.net for your self though. Now let’s get to it!
First off, there are 30 possible key signatures; 15 for major scales, and 15 for minor scales. You don’t have to memorize all 30 though! Using the key signature calculation method described on musictheory.net, each key signature is assigned a numeric value based on the number and type of accidentals (Sharps or Flats). Sharps are positive; flats are negative. You end up with 7 Sharps (positive) and 7 Flats (negative), so in theory you only have to remember 7.
A major has 3 Sharps (+3)
B major has 5 Sharps (+5)
C major has 0 accidentals (0)
D major has 2 Sharps (+2)
E major has 4 Sharps (+4)
F major has 1 flat (-1)
G major has 1 Sharp (+1)
Now we will look at Cb, C, and C#:
Cb has a numeric value of -7 (7 flats).
C major has a numeric value of 0 (no accidentals).
C# has a numeric value of +7 (7 sharps).
Notice that Cb is 7 less than C major, and C# is 7 more than C major.
Now lets try a hard one: Db major;
We know D major has a numeric value of (+2), if we subtract 7 from this we get -5 (5 flats). So Db major will have 5 flats in its key signature. D# major would be +2 plus 7……… ut oh! That is +9, what do we do now? Well this is where I got lost, D# major is actually Eb major which would have a numeric value of -3 or 3 flats right? So I am guessing it is not musically correct to right down 9 Sharps for a key signature, and 3 Flats should be use instead, but won’t this effect chords used in this key? We will find out later.
Let’s look at minor now.
We know C major has 0 accidentals, so c minor will have -3 or 3 Flats. You guessed it; all we need to do to convert a major to minor scale is subtract 3.
For example E major (+4) converted to e minor is (+1): E minor will have one Sharp.
What if we want to convert G major (1 sharp) to G# minor? This would require us to use two conversions. One conversion from major to sharp, and another from major sharp to minor sharp. For example G major 1 + 7 = 8, now we want to subtract 3 for a total of 5. Therefore G# minor will have 5 Sharps, which if you are paying attention is the same as B major!
Sharps are shown in a particular order in the Key Signature: F#, C#, G#, D#, A#, E#, and B#.
Flats are also shown in a particular order: Bb, Eb, Ab, Db, Gb, Cb, and Fb.
Remember order of Sharps in key signature with:
Father Charles Goes Down And Ends Battle
Remember order of flats in key signature with:
Battle Ends And Down Goes Charles’ Father
By now you should have a good handle on how to determine the key of a song by counting the number of Sharps or Flats in its Key Signature.
Now lets look at what chords make up each key so if we don’t know the key signature we can still determine the songs key.
In order to figure out the key of the song based on the chords being played, we need to understand chords first. This is pretty basic, but for those that don’t know a chord is constructed of 3 or more notes. These chords are based off of one note, and that note is called the ROOT note. If you were to play a G major chord on the guitar, the first note you hit is a G note, and you guessed it, that is the ROOT note of that G chord. In a G major triad (G major chord) the second note would be a generic 3rd, and the third note would be a generic 5th. To move from the root note of the G major chord to the generic 3rd on a guitar you would count up 4 frets (on piano this would be 4 keys). On guitar we would switch to the A string to accomplish this, and play the second fret which is the note B, because just moving up 4 frets on the same string would not get us anywhere. To move up to the generic (perfect) 5th we would count up 7 steps (frets or keys) to a D note. Again in standard tuning, we would play this on the high E string (3rd fret). So long story short, a G major triad is composed of the notes G-B-D. There are way too many other chords to go into, so I suggest you visit musictheory.net to visit how chords are constructed. They also have a very nice chord calculator, in case you are having trouble with strange chords.
Now we will analyze a song to see which key it may be in. Follow along at musictheory.net
For this example the key signature has 3 flats, which would mean our key is either Eb major, or C minor.
The first chord in this example contains an Eb, Bb, Eb, and G which we know is an Eb major triad. This is chord I in Eb major, so we are most likely in that key. Remember how I said that the first chord is usually what key you are in?
Now you are asking yourself, “wait where the hell did that ‘chord I’ thing come from” well I will tell you. Keep in mind that this is where I gave up on guitar lessons, because I was 13 and wanted to play Eruption, not figure this stuff out.
When you analyze music, each diatonic triad can be identified with a roman numeral. There are 4 different triad types, Major, Minor, Diminished, and Augmented. Each type is represented differently as follows:
Major – Uppercase
Minor – Lowercase
Diminished – Lowercase with a circle
Augmented – Uppercase with a plus sign.
For simplicity sakes (and to keep me from going nuts) lets start with a song that has the following chord progression:
Verse = G-C-G-C | Chorus = E minor-D-C-G (Every Rose has its Thorn?)
Because I don’t know any better, and the song starts with a G chord, let’s guess and start analyzing the song using the G Major scale: G, A, B, C, D, E, F#, and G
Now we build diatonic triads on top of each note in the scale starting with the G, which if you remember from above was G-B-D, and was a G Major chord.
So our first chord in the progression contains the first triad of the G major scale we built, so it gets an uppercase roman numeral 1 or I.
The second chord is a C major, so we look through our G major scale for a C major triad, and what do you know, there it is. C-E-G.
The C major triad is our fourth triad in the scale, so this chord would get an uppercase roman numeral four (IV).
Our third and fourth chords are G-C respectively so there is no need to re-analyze them.
So far using a G Major key we have this progression I-IV-I-IV
Now for the chorus; which starts with an E minor. If we build a diatonic triad using E for our root we get E-G-B, which you guessed it is an E minor.
Since an E minor triad is our sixth triad in the scale, we would represent this with a lower case vi.
We do this for the remainder of the chords in the song, to find that every triad is found within this songs chord progression. So lucky me…… this song is in the key of G!
Phew…..That was a lot of work, and I am tired (and some what confused)…. I think I will let this sink in, before I move on to another topic! Stay tuned…