Passion

When he touches the keys

The great velocity of a pressed key

Produces

The greater force of the hammer

Hitting the string

The louder the sound of the note produced

I know when he plays the piano

He is well

He plays with passion

He plays with love

It effects his emotions

Influences his character

Calms his soul

He is free

He is at one

With the piano

I also know when he is unwell

That is when he does not play.