Don't Selfish

Learn To Play Piano Instantly: #2 Beginning Training.( Part 2 )

Credit to : InstantPianoGenius 

Learning how to play piano by ear is not that difficult. Once you have the melody figured out, all you have to do is harmonize it with chords. After that, you could experiment with different chord voicing to vary the sound. After practicing for a while, you will know how to play piano.