invisible (sometimes)

I am a sound not an image,

I am a shape with no sides.

I can look in the mirror,

and find I am empty inside.

I can walk down the street,

like a ghost with no past,

as people look through me,

as if I am made of glass.

I come alive in the night,

like Dracula coming out from the shadows,

and in the day,

I am sombre and mellow.

So sometimes the world is my playground,

when I appear invisible.