No paint was really wasted...

In the picture they all were
smiling and have fun.
In reality the posing group was
frowning and having none.
Could it be the picture painted
was in reality tainted?

The picture hung on the wall
the subjects sat in the hall.
The music was playing 
the atmosphere was decaying.
No one was dancing on the floor
the artist wanted to hit the door.

While he was painting,
they all held their smiles
without fainting.
The artist all of a sudden awoke,
it was a nightmare,
he hadn't painted one stroke.
He walked over to his canvas bare
just stood and gave it a long stare.

One