The following question came over email and I thought others would benefit from it.
How long exactly should chord progressions be? For example I assumed that all chord progressions were four bars long and consisted of just four chords each being played one bar long and then repeating the whole time throughout the song. However, chord progressions can be long and they can include more than 4 chords? Also how many chords is too many in a chord progression? Or does it depend on length. Also chord progressions can change throughout a song? I guess depending on where one is in the song correct? For example, the chord progressions can be different during the breakdown, bridge, and chorus of the songs? All in the same key of course though!
There’s really no set rules on the length of a chord progression, so it’s really up to you. While many songs do just use 4 chords that repeat over and over, this is certainly not the norm. Some dance music for example can have as little as 1 or 2 chords the entire song, where as some pop ballads can have upwards of 32 chords before the progression repeats.
Choosing the number chords in your progression as well as the rhythm (when the chord changes occur) is a stylistic choice that depends on the genre of your song and the sound you are going for. Dance music for instance tends to have simple chord progressions so that the music is more memorable and predictable. Having more chords can make your song sound more complex which can help you to create a more unique sound.
While some songs have the same chord progression throughout the entire song, many songs change chord progressions between the verse, chorus and bridge. This can help you to create more emphasis when transitioning between sections.
In our next book, Hooktheory II, we’ll have a chapter on how you can play with changing the chord progressions between sections to create different types of sounds.
Ryan, is there a music theory that guides creating a chorus to a verse or vice versa? I've got some progressions and I'm able to make them into songs occasionally but I'd like to know the underlying theory of that. Does Hooktheory support it?