DESCRIPTION:
Music Theory doesn't need to be hard.
Here I show a guitar student of mine how to play all the basic chords on piano in about 3 min! It should only take you 15-30min of practicing building these chords to get fast at it. Write down how many keys to skip in case you forget:
Major = 3 2
Minor = 2 3
Dom7 = 3 2 2
Min7 = 2 3 2

EXTRA INFO: To be clear there is a difference between a Dominant 7 chord written C7 and a Major 7 chord written Cmaj7. To make a maj7 chord you must skip 3 after making your Major chord so it would be skip 3 2 3 to make a Cmaj7.