however, most of my students tend to ask the same question as soon as i give them something to play over: "wait, what key is this in?"
today we're going to discuss some simple and logical ways to figure out what key you're in on the spot, without taking too much time or asking out loud. after all, sometimes the band is too loud to speak to you! onward...
we're going to pull up the diatonic chord structure for some reference to help us out...
I Major
II Minor
III Minor
IV Major
V Major
VI Minor
VII Diminished
we've discussed before that chords appear in this pattern in every diatonic key. because of this, we can use it to help us determine what key a particular chord progression is in by looking at how the chords are built. let's take a look at this example progression...
E- D- Gmaj A-
the clue here is in the chords that fall next to each other in the alphabet. in this case, D- and E- are the clue. there is only one spot in the diatonic chord structure that allows for 2 minor chords to be next to each other, and that is the II and III positions...
I Major
II Minor
III Minor
IV Major
V Major
VI Minor
VII Diminished
therefore, we know now know that II = D- and III= E-. this only occurs in C major. success!
some of you might be saying to yourself, "but A- and Gmaj are next to each other in the alphabet as well. how come you didn't use those chords?" the answer is simple - a Major chord followed by a Minor chord happens twice in the scale structure (I->II and V->VI). this would have narrowed down the key possibilities to two, but in this case that wasn't necessary.
another example...
DbMaj EbMaj F- AbMaj
this one should be easy. we've got 3 chords in alphabetical order here. two Major chords next to each other, followed by a Minor? that's gotta be IV, V, and VI. yup, we're in Ab Major.
this is all well and good, but so far we've only been looking at chord progressions that have triad-based chord structures. what happens if we don't get full triads, like in a power chord jam, or even worse, a single note riff that might not imply chords at all?
enter some note analyzation. remember how to play that major scale?
|---------------------------------|
|---------------------------------|
|---------------------------------|
|-------------4-5-----------------|
|-------1-3-5---------------------|
|-1-3-5---------------------------|
let's convert this major scale to a one string setup. this way we can see all the whole and half steps that make up this scale...
w w h w w w h
|-1-3-5-6-8-10-12-13-|
given a power chord or riff based progression, we're going to be forced to use the notes themselves instead of the chord structures to help us out. imagine we're playing over a certain punk rock tune from the 90s (fill in your own rhythm)...
Eb5 Bb5 C5 G55 Ab5 Eb5 Ab5
we've got 5 notes to go by in this example...
Ab Bb C E G
again, we're taking an interest in the notes that happen to be next to each other alphabetically, but now we're also interested in the half and whole steps that occur between them as well. since the major scale consists of more whole steps than half steps, the halves are much more valuable. we've got one set in our little green riff, and it falls between G and Ab. so now we know we've got two possible scales...
Ab Bb C x Eb x G
and...
Eb x G Ab Bb C x
hmm... still not enough information! let's have a look at this progression in tab format...
|------------------|
|------------------|
|------------------|
|-8----------8-----|
|-6-8-10-5-6-6-8---|
|---6-8--3-4---6---|
each power chord consists of TWO notes. let's add those extra notes into the mix, and we end up with...
Ab Bb C D Eb F G
looking like we have a lot more options here. now all that's left to do is arrange the notes around so we have the only way to make the whole and half steps appear in the right spots. we end up with...
Eb F G Ab Bb C D
Eb major!
wow, that was a lot of work! well, not really. the first few times you try to figure out what key you're in on your own it might take you some time, but after a few tries you'll not only start to remember these tricks, but you'll begin to hear them as well. most people playing through this basket case of a riff will be able to pick out that they're in Eb major just by hearing it. if you can't, though, there's always these tricks we spoke about today. check for chord qualities, notes and chords that fall alphabetically next to each other, and for the arrangement of half and whole steps. with practice, you'll be able to hear and feel each key in less and less time.
until next time, grasshoppers!