As a result of this, the guitar parts are often played with slightly different chord inversions, or a reduced number of notes played to free up space for the keys. This 4 string take on a Major 7 ...

You’ll notice each major 7 chord has its own ‘EQ’ due to the different strings used. I’ve highlighted A for particular attention here because it’s such a nice key on the guitar ...

Harmonic minor keys are used when writing chords. There is another version of the minor key known as the melodic minor. This is used when writing a melody. Each key signature has two possible keys.