Let's do all the keys!
Your chord-type mastery and ability to play them comfortably and instantly in all twelve keys is one of my ambitions. If you neglect this practice, you are only making your own journey more difficult: you will hesitate more, you will struggle to remember progressions, improvising will be impossible and your general key mastery and fingers-on-keys time will all be jeopardised.
My remedy to this mountain you must peak is to give you the opportunity, four chords at a time (per video), to play them along with me slowly, until you can do them yourself more quickly. To date, there are two videos but I will add one or two more including even more chords (even jazz extensions - and this article will be updated at the time). In the videos, I give you the template of the four chords to be mastered before playing them through all keys, moving chromatically to the next key and giving each chord two beats. You are naturally encouraged to pause the video when required to verify the shape. I further propose to play them with your eyes closed and go straight into doing it with both hands since both hands play chords, not only the left!
Water Pianism Syllabus Overview Document
(auto PDF download)
Video 1 provides you with the four primary chord types, which means the only 4 possible variations of 1357 in which the 3rd and 7th are altered, giving: M7 (1 3 5 7), dominant 7 (1 3 5 b7), m7 (1 b3 5 b7) and mM7 (1 b3 5 7), this last being the least common but still needing to be understood.
The second video gives you the next (but not last!) four in-octave chords: 6th (1 3 5 6), m6 (1 b3 5 6), whole diminished (1 b3 b5 6) and half-diminished, also known or written as m7b5 (1 b3 b5 b7). The more you play along, the more you'll get familiar with the tiny finger movements required. I have ordered them in such a way as to limit multiple finger movements to enhance precision.
A similar playlist which takes you through very important fundamentals step by step is my Absolute Major Scale Mastery Playlist, the first video of which is provided here: