You'll notice that there are 15 major and 15 minor keys on this diagram. If Cb = B, Gb = F# and Db = C#, that
makes the number 12, the same as the number of notes. The number of possible modulations and key-changing
effects within this apparently limited number is extraordinary. There are a number of ways in which the relative
distance of keys can be assessed. Here is one:
As you can see from this table, adjacent near keys tend to have three or four chords in common, making it easy to
change from C major to any of them. Use the chord table in Section 3 to find common chords.
Key Changing for Guitarists
Changing keys is more problematic for guitarists than pianists because of the fingering problems that may arise. This
is one reason why songwriter-guitarists tend to use less modulation than songwriter-pianists. For example, take a
song whose verse and chorus are in A, with plenty of open-string chords. If you raise the key a semitone (half-step)
to Bb, five of the six primary chords turn into barre chords. Guitarists would therefore tend to favour changing to a
key that has easier chord shapes.
You can exploit this characteristic of the guitar by reversing the scenario. Start in a key that requires barre chords
and then modulate up a semitone (half-step) to a key with open-string chords. The change in the timbre of the chords
can be striking. Try B into C or F# into G or D#m into E minor. The effect is further complicated by the resonance
of certain chords against others – according to how many strings are in the chords. If you write an introduction in an
awkward key, at least you won't be stuck in it for very long.
Keys and Their Associations
On the guitar, A major and E major are both associated with rock, the latter especially with heavy rock, with B and
F# as also-rans. The keys of D, G and A are popular in indie/"jangle" styles because of the ringing open strings.
R.E.M. had a long-standing love affair with E minor. Oddly, C has never been a popular rock key.
Some players have marked preferences for certain keys. Mark Knopfler's early songs were often in F and D minor.
Blues players who detune a semitone (half-step) often end up in Eb and Ab by default, as in 'Voodoo Chile (Slight
Return)' and some of Stevie Ray Vaughan's songs. Songwriters sometimes build up personal associations with keys
- they have "hot" keys and "cold" keys, "summery" keys and "wintery'' keys.
The keys of Eb and Bb are suited to brass instruments and are associated with 1960s soul/Motown. The Celtic harp
is usually tuned to C minor, so it has Celtic folk associations (listen to the music of Breton harpist Alan Stivell). F
minor is a favoured key for James Bond music – session trombonist Don Lusher once said, "If we got a booking for
a Bond session with John [Barry], it'd be, 'Oh yes. That'll be another week of F minor then.' It was always F minor.
You could bet on it!". This came true yet again with 'The World Is Not Enough'.
Which Keys Suit the Guitar?
The natural keys for the guitar are those in which the open strings can be maximised. These range from F to E, with
their attendant minors. Here are the major keys, with the number of open-string chords in each (this covers chords I-
VI plus the bVII):