Suppose a song is in C Major, its chord progression will most probably contain the chords from the family of C Major.
Chord Families
Once you get famliar with chord families, finding the right chords of a song becomes easy. You just have to know how to determine the key of a song. Once that is fixed, all you have to do is start adding chords from a chord family. Suppose a song is in C Major, its chord progression will most probably contain the chords from the family of C Major.
C Major/A Minor
D Major/B Minor
E Major/C# Minor
F Major/D Minor
G Major/E Minor
A Major/F# Minor
B Major/Ab Minor
