This idea goes back decades. I started teaching this to small children, but it worked just as well for teens and students of all ages. It took me a couple hours to come up with the Oreo pictures! The idea is to learn all 12 of your major chords by color groups. Then you double check your answer is by counting keys.
The rest of the story:
To this very moment the Oreo cookie concept remains one of the most successful ideas I’ve ever had, and it works for everyone. It works for children as young as age four or five. But it also works for preteens, teens,and for adults of all ages, in other words, the idea is equally useful regardless of how old you are.
The key is grouping the chords. Here are the groups:
- All white: G C F
- Reverse oreos: E A D
- True oreos: Eb Ab Db
- All black: Gb or F# (two names for the same chord_
- The two oddballs : Bb and B
Circle of 5ths or 4ths:
Bb Eb Ab Db Gb :::::::: B E A D G C F