When we are counting through the semitones from, for example
D to
E, it doesn't matter whether we say "D,
D# E, or "D
Eb E" because we are just passing through them, not stopping on them. That's why I showed the notes both ways in the previous examples, as, for example,
A#/Bb
However, if the chord of the new key has two possible names, we should choose the correct name depending on the key.
For example, let's say we have a two-chord song in the key of C major as follows:
C, Em and we want to transpose it down to the key of
A major.
C becomes A
Em becomes C# m (not
Db minor)
Why not
Db minor? Because The key of
A major doesn't contain any note named
Db. It has the following notes:
A B C# D E F# G#
It has NO
Db only
C#
Of course, if we use the wrong name, it won't sound any different when we play the song, but on paper, it will be incorrect. To know which one to use for all situations means knowing the major scales for all the keys:
Here they are for reference:
Ab MAJOR = Ab Bb C Db Eb F G
A MAJOR = A B C# D E F# G#
Bb MAJOR = Bb C D Eb F G A
B MAJOR = B C# D# E F# G# A#
C MAJOR = C D E F G A B
Db MAJOR = Db Eb F Gb Ab Bb C
D MAJOR = D E F# G A B C#
Eb MAJOR = Eb F G Ab Bb C D
E MAJOR = E F# G# A B C# D#
F MAJOR = F G A Bb C D E
F# MAJOR = F# G# A# B C# D# E#
G MAJOR = G A B C D E F#
If we want to know the correct names for notes of the minor keys we can just take any major scale and begin on the sixth note. That automatically produces the correct notes for the minor scale starting on that note, for example:
G A B C D E F# = G major
E F# G A B C D = E minor
They have the same notes but different starting points. That's why E minor is called the
relative minor of
G major. That's true for all major keys and their relative minor keys. The sixth degree of any major scale is the first degree of its relative minor.