Defining JOY

I have so been enjoying this season of intentional anticipation- as I was awake (annoyingly) at 2a.m. again last night I was thinking about JOY. We talked last night at dinner about what the different characters in the nativity story had to be joyful about.
Mary- I'm sure she was joyful that her labor was over!
Joseph- Knowing that his wife was chosen by God because no one could make up a story like that!
What about the angels (this one stumped us)- They were filled with joy so much that they broke out into song about it. Perhaps seeing the Word being fulfilled.
And those shepherds- they went and told everyone around their joy-filled news.

That was what had me thinking about defining JOY- an inward contentment with an outward expression.
Somewhere around 3 a.m. I remembered that I have forgotten all about this song- what great lyrics to meditate on as I consider my level of inward contentment and my outward expression of it...

Come thou long-expected Jesus,
Born to set Thy people free;
From our fears and sins release us,
Let us find our rest in Thee.
Israel's strength and consolation,
Hope of all the earth Thou art;
Dear Desire of every nation,
Joy of every longing heart.

Born Thy people to deliver,
Born a Child and yet a King.
Born to reign in us for ever,
Now Thy gracious kingdom bring.
By Thine own eternal Spirit
Rule in all our hearts alone;
By Thine all-sufficient merit
Raise us to Thy glorious throne.