Music Theory- What is a 'Key'?

Pop songs are always in a ‘key’. This means they use certain chords that go together well, which are derived from corresponding the major scale. Music teachers always explain the key of C first as it has no nasty ‘sharps’ of ‘flats’.

Chords in Key of C

These chords can be seen like colours that go together well- meaning any of these are a safe choice and a song in the key of C would mainly use these chords and few others, if any. As well as the chords, we can play notes from the C major scale (next page) over the top of these for the melody

Chords + melody = song

Example chord sequences in the ‘Key Of C’

Key of C guitar chord progression 2

Key of C guitar chord progression 1

Here is an old lesson page that I created on the 'Key Of G'. I decided to swap it to the key of C for this beginners course- but if you want more on this essential topic- here is all about The Key Of G!

The Key Of G

A key can lock or unlock a door. It is also a way of knowing which chords sound good together, and what melodic notes will also work over these chords. It can be seen as a 'family of chords' or a 'pallet of chords'. The name of the key is the same as the first chord option, known as the Tonic.

How can I know the key of a song?

The best thing to keep in mind is- more often than not, the key of the song is;

  • The first chord in the chord sequence
  • The last chord in the chord sequence
  • The most common chord in the chord sequence

If 2 or more of the above applies, then that is usually the key (it doesn't always need all 3!) At this Level, we're looking at the 'Key of G'. Practically, this means that G will likely be the first chord in the chord sequence, or the last, or crop up the most out of any chord in the song. However, it is the other chords in the song, the 'family' of chords, that tell us we are in the key of G.

Common chords in the Key of G

G - Am - Bm - C - D - Em

Put simply, if a song uses these chords in any order, it is in the key of G. If a song uses say, Dm, instead of D, that usually means the song isn't in G (even though it could be- more detail on this at level 8)

It is no coincidence that these chords are in alphabetical order. For now, you should get that these chords can be in any order. You should find it always 'works' and there isn't ever a chord that sounds wrong.  However, there are some well used chord sequences that just happen to crop up in 'hit' songs again and again.

Example chord sequence 1

(Similar to Stand By Me by Ben E King)

|G                      |G                      |Em                     |Em                    |

|C                      |D                      |G                         |G                        |

The first chord is G, the last chord is G, G is the most common chord. Also ALL the other chords in the song are from the pallet of chords we expect (listed above). THIS becomes more and more important as it is the reason as song is in a particular key, so try and remember them.

Example chord sequence 2

This is nicknamed a '4 chord song' as it is so common in 'hit' pop songs.

|G                      |D                      |Em                     |C                        |

See the amazing video below for examples! I teach the chord sequences they use in these videos here 4 chord songs! :)

Its important to remember that rules in music can always be broken. Songwriters go with whatever sound good. So a song can be in a key but have other chords in it that we may not expect.

Example chord sequence 3

This sequence had an A major chord and an E major chord, when both 'should' be minor. This really fits in the song, giving it a chilled Jazz feel.

Sitting on the dock of the bay- Chorus

|G              |E               |G              |E               |

|G              |A               |G              |E               |

Recap on Keys and the key of G!

More often than not, the key of the song is;

  • The first chord in the chord sequence
  • The last chord in the chord sequence
  • The most common chord in the chord sequence

Common chords in the Key of G are G - Am - Bm - C - D - Em but others can be used

One of the most common chord sequences used in hit songs is known as a 4 chord song. This chord sequence in G is  |G                      |D                      |Em                     |C                        |

Now you know the most common chord sequence ever, put these chord sequences into practice with the most common strumming pattern ever- Down and up strums with a tie with this strumming lesson!

Strumming Stage 6- Old Fav

Or learn some examples of songs in the key of G!