Shared Chord Tones

A very commonly used concept in film music to write chord progressions is the concept of shared chord tones. Basically you could treat every chord as a new tonic and find the next chord by moving to a chord that shares at least one chord tone with the old chord.

Even though these chords might harmonically be extremely far apart, the shared chord tone will create a sense of cohesiveness and connect these chords. This works also if these shared chord tones are higher up in the chord structure (e.g. maj7, #11) which also allows to practically connect any chord with any chord.

A mixture of this principle with the principle of harmonic modal interchange and “traditional” cadential movement will give you a very nice and modern filmic chord progression. A great example for this technique is Danny Elfman’s Spiderman Theme from 2002.

One thing to remember is that there are also other analytical approaches to understand (parts) of these chord progressions which make sense as well. In such situations, often analytical concepts overlap and different interpretations are possible. A good guide might be to ask “How do I hear it?” – in the example above, it is very hard to point out a tonic center that lasts longer than a few bars but the connection of chords over shared notes seems way more plausible here (also noticeble by observing the busy string ostinato in the background which only slightly shifts the tones it uses from chord to chord.)