They are so commonplace that we take the theory behind them for granted. Here are five 7th chords, the theory underpinning them, and some ideas for modifying them ...

The examples below provide further explanation! As a reference point, here is a G7 chord. These contain a b7th, which is referred to as the dominant 7th (and not considered as ‘altered’ in the ...

The general theme with these shapes is the dominant 7th sound, which is essentially a major chord plus a b7th. This is a great way of injecting some ‘blues’ flavour into your chord progressions.