The Piano as far as I know plays one note per press of key,movement of mechanical linkage strike of hammer.
Its a percussion thing innit?
If I pluck a string on a guitar the note is sounded and while it is sustained I can then manipulate it in various ways, bending ,pulling hammering on sliding.
A good player can achieve a lot with each sounding of each string.
On the piano (of which I am ignorant)once the hammer falls the note is made.
Paco O'Barmy.
Thanks for that re the pedals.
I knew there was some sort of damping /sustain available but can it change the note?

Howard Jones
I like to hear the piano and it is in its own way very expressive ,usually with music written for it?

But I don't think it has any human qualities in the same way as other instruments do.
I don't regard it as lesser just different.

PS Anyone tell me why some pianos have three pedals and others two?