Summary
Highlights
The first chord trick discussed is the major line cliche, where one note in a major chord moves by semitones. This creates a C major 7 chord and a C dominant 7 chord from a C triad. Strategies to adapt this include changing the key, tempo, time signature, or the line cliche's movement (descending and then ascending). "Michelle" by The Beatles and "Kiss Me" by Sixpence None the Richer use a similar concept.
The minor line cliche is similar to the major one, but it starts from a minor chord. In George Harrison's "Something," it appears in the second half of the verse, moving an 'A' note down in semitones to create an A minor major 7 and then an A minor 7 chord. To adapt this, one can use it on different minor chords in a key or move the chord progression to a different part of the song, like the bridge. Bruno Major's "Nothing" and The Beatles' "Eleanor Rigby" feature similar techniques.
Secondary dominance involves a dominant type chord (dominant seven) whose root is a perfect fifth above the target chord, and it always precedes that target chord. In "Something," a D7 chord precedes a G chord. This allows for many variations, as almost every chord in a key has its own secondary dominant. For example, using the secondary dominant of the six chord (A dominant 7 for an A minor in C major) creates a unique sound.
The magic chord modulation involves a key change into the bridge of a song using a 'flat seven major' chord. In the key of A, the G major chord is the magic chord because it's the flat seven of A. This chord, while not diatonic, sounds good in any major key, evoking blues, R&B, and soul. George Harrison used the G major as a pivot chord to modulate from C to A, as it functions as the V chord in C and the flat seven in A. This can be adapted by starting in a different key and using its V chord as a pivot to a new key where it functions as the flat seven.