iTunes' top 10 selling singles and albums of the week ending Jan. 4:

Singles:

1. "Tik Tok," Ke$ha

2. "Bad Romance," Lady GaGa

3. "Fireflies," Owl City

4. "Replay," Iyaz

5. "Empire State of Mind (feat. Alicia Keys)," Jay-Z

6. "Down (feat. Lil Wayne)," Jay Sean

7. "Party In the U.S.A.," Miley Cyrus

8. "Whatcha Say," Jason Derulo

9. "I Gotta Feeling," Black Eyed Peas

10. "Sexy Chick (feat. Akon)," David Guetta

Albums:

1. "The Fame Monster (standard)," Lady GaGa

2. "Ocean Eyes," Owl City

3. "Alvin and The Chipmunks: The Squeakquel (Original Motion Picture Soundtrack)," Various Artists

4. "Fearless," Taylor Swift

5. "Battle Studies," John Mayer

6. "Glee — The Music, Vol. 2," Glee Cast

7. "Avatar," James Horner

8. "My World," Justin Bieber

9. "Only By the Night," Kings of Leon

10. "The E.N.D. (The Energy Never Dies)," Black Eyed Peas