In case you're wondering what the hell Princess Leia was singing, you'll now know. Carrie Fisher isn't that bad a singer, but considering that the lyrics are abysmal and she was totally high at the time...
Inside some kind of ceremony hall, there's a bunch of Wookies in red robes. There's a platform at one end of the hall. Luke, Han and Leia run onto it. Han mumbles about how glad he is that he can be here, and then:
LEIA
(to Wookies)
This holiday is yours, but we all share with you the hope that this day brings us closer to freedom, and to harmony, and to peace. No matter how different we appear, we're all the same in our struggle against the powers of evil and darkness. I hope that this day will always be a day of joy
in which we can reconfirm our dedication and our courage. And more than anything else, our love for one another. This is the promise of the "Tree of Life".
Some horrible twangy instrument starts playing the Star Wars main theme slowly.
LEIA
(singing with eyes glazed over)
We celebrate a day of peace.
A day of harrrr-mon-y-y-y-y-y-y.
A day of joy we all can share together joyously-y-y.
A day that takes us through the darkness.
A day that leads us into might.
A day that makes us want to celebrate....the li-i-i-i-i-i-i-i-i-i-i-ght.
A day that brings the promise that one day, we'll be freeeee...to live...to laugh...to dream...to grow...to trust...to loooooooooove...to beeeeeeeeeeee.
Leia and the music abruptly stop.
Cue credits.