You can build the 3 main types of 7th chords from just one shape and two small moves. In this video I'll show you the system, and then we'll practice it together through all 12 keys along to a backing track.

If you know a few 7th chords in a few keys but get stuck the moment you're somewhere unfamiliar, this exercise fixes that.

All you need to know are your major triads - from there you'll be able to build major 7, dominant 7 and minor 7 chords anywhere on the piano