Definition Poem

It springs into life as soon as it is touched,
Vibrant with movements that shiver our ears.
As the keys snap open, the beauty is released,
Ranging from high and sharp to the low and deep.
The beauty itself can be quick and stabbing, tranquil and silent,
Or solitary and stately. The possibilities are infinite.
And as the workers are uncovered,
There is a machine inside, hard at work
Producing a new, unique product every time somebody else starts it.
What is made cannot be worked up by wandering words.
What is it?