HOLLYWOOD, California (CNN) -- Singer Christina Aguilera joined fellow Grammy Award winners Alicia Keys and John Legend for "CNN Heroes: An All-Star Tribute," which honored the top 10 CNN Heroes of 2008.

Christina Aguilera performs her hit single "Beautiful" at "CNN Heroes: An All-Star Tribute."

The show, taped before an audience of more than 2,500 at the Kodak Theatre in Hollywood, premiered on the global networks of CNN on Thanksgiving night.

Liz McCartney, dedicated to helping survivors of Hurricane Katrina rebuild their homes, was named 2008 CNN Hero of the Year.

McCartney, who will receive $100,000 to continue her work just outside New Orleans, was selected from among the top 10 CNN Heroes after six weeks of online voting at CNN.com. More than 1 million votes were cast.

"To the country and the world, I ask you to please join us," said McCartney, of St. Bernard Parish, Louisiana. "Together we can continue to rebuild families' homes and lives. ... If you join us, we'll be unstoppable."

Hosted by CNN's Anderson Cooper, "CNN Heroes: An All-Star Tribute" featured musical performances by Aguilera, Keys and Legend.

Keys sang "Superwoman," her tribute to women around the world, from her hit album "As I Am." Aguilera performed her hit single "Beautiful."

Legend, backed by the world-renowned Agape Choir, performed "If You're Out There," from his just-released album, "Evolver."

All three performances echoed the spirit of the CNN Heroes campaign, which salutes everyday people accomplishing extraordinary things in their communities and beyond.

"In this time of economic turmoil, it is such a relief to know that there are people like these heroes, people who care more for others than they do for themselves," Cooper said.

Answer the following questions:
1. What state did the performance take place in?
2. Was there an audience?
3. How many people?
4. What was the name of the venue?
5. Who was the performance in honor of?
6. What had she done to be honored?
7. Who were the singers at the show?
8. Which award had all of them won before?
9. How was McCartney selected as the winner?
10. How many people voted?
11. How long was voting open for?
12. Where could you vote?
13. Who was the program's host?
14. What does Cooper think it's relieving to know?
15. When was the program aired?
16. What song did Keys perform?
17. Which record is that from?
18. Who did Legend perform with?
19. What kind of people does the campaign praise?
20. What song did Aguilera sing?
1. california
2. yes
3. more than 2,500
4. Kodak Theatre
5. Liz McCartney
6. helped survivors of Hurricane Katrina
7. Christina Aguilera ,Alicia Keys and John Legend
8. Grammy Award
9. online voting
10. More than 1 million
11. six weeks
12. CNN.com.
13. Anderson Cooper,
14. to know that there are people like these heroes
15. Thanksgiving night.
16. Superwoman
17. As I Am
18. If You're Out There
19. people who care more for others than they do for themselves
20. Beautiful