13. Recognizing Key Signatures. Transposition.
Key Signature Finder Chart
A key signature tells a musician in what key the music is played. It simplifies the music notation, but more importantly it tells what chords should be played with sharp or flat in relation to C-Am key. First, how to recognize a key. Every key signature designates two keys: a major and its relative minor. Let us put two symbols of notes which are the roots of those keys beside their key signatures like on the chart:
Do you notice the relation between these two notes and the rightmost accidental symbol? The rightmost sharp is always between the notes. The rightmost flat is below and always in the same proportion! If you know this very simple rule, you immediatelly can say in what key the musical score is. And you immediatelly know the relation between the major and its minor keys just imagining note symbols on the staff. How the signature of Db-Bbm indictes that the keys are flat? Because there are flats in the signature which indicate that this B is flat and this D is flat.
When you take any sequence of chords in C-Am keys and want to play it in (transpose to) the other key, the roots of the chords of the transposed sequence should follow the rule of the key signature: half step up or down in accordance with sharps and flats in the key signature. The next example will illustrate it.
Here is the sequence of notes of the A minor key: A B C D E F G A. After G we close our circle of notes coming back to A. Pretty straightforward, isn't it? What happens if we start to play chords starting from A as the root stepping over two notes until we come to A again? Like in the sequence below:
A B C D E F G A B C D E F G A B C D E F G A (or ADGCFBEA: A Devoted Guitarist Can Feel Better Eating Apple)
The chord order should be: Minor, Minor, five Majors, and the final Minor, or shortly Amin Dmin G C F B E Amin. What happens? It sounds great! We are going over every note out of seven and we do it in the sequence of the circle of fifth. There are 8 chords in the sequence. The last chord is the same like the first one. This is a chord progression on which innumerous musical pieces are build upon. Playing it in 8 bars makes simple but beautiful music. Let us transpose it starting from any note as the root of a new key jumping over 2 notes (since it is the same sequence) with the same chord type order. Easy, but there is a caveat: it does not sound right. We have forgotten about sharps and flats! Here is an example, how key signatures are helping us to find them.
1. Let us start the sequence, say, from C meaning trasposing to C minor. So the sequence of chord roots will be: C F B E A D G C. The first two chords are minor, and the rest are major, so we can write it down like this: Cmin Fmin B E A D G Cmin
2. Let us look at the key signatures. There are two signatures in which C on the position of a minor root is present: with 4 sharps and 3 flats. One with the sharps does not fit since one of its sharps makes C C#. Therefore the signature we are looking for is the one with 3 flats.
3. Then taking the flats in account our sequence becomes Cmin Fmin Bb Eb Ab D G Cmin. This is it. As an exercise try to transpose ADGCFBEA sequence to Bb minor.
On guitar, a chord progression played in different keys sounds very different if you try to take every chord closer to the headstock. And transposing to another key on the guitar is very simple in comparison to, say, piano, because the fingering shapes of chords are the same. This is a simple method, a guitarists advantage to make an interesting "concert". Take for example Bb minor key. The part Bbmin, C, F sounds very different from the A minor key corresponding part Am, B, E.