Welcome to episode three of How to Fake Playing Piano. In lesson one, composer Jason Oberholtzer taught you what to do with your left hand. In lesson two, he taught you scales and the key of C major. Today he'll show you chords, and keys outside of C major.
As far as I - someone who barely understands music, as demonstrated in the video - understand, Jason is taking the "learn three chords" approach from guitar lessons, and applying it to the piano. It isn't how you learn to be a concert pianist, but it teaches you enough to have some fun.
I had trouble following along as Jason taught me the key of D. For now I'm gonna stick to the key of C. But if you caught on much faster than I did, now a whole world of music is opening up to you.
This is the part where even with our shortcuts, you won't learn much without practise. But your practise can be freeform - you don't have to bang out "Mary Had a Little Lamb" a hundred times.