Dave Clews
When writing a song, whether you intend to or not, you’ll work in a particular key. You might start out by saying “right, this will be in C minor”, or you might just string together a seemingly random set of chords that, when analysed, happen to conform, to a particular key. Each key has its own set of seven chords that belong to it, from the seven notes of the parent scale of that key. These are known as the diatonic chords for that key.