Tops on iTunes

The top singles on iTunes for the week ending Feb 10.

1. "Dark Horse,"

Katy Perry, above,

featuring Juicy J

2. "Happy (from 'Despicable Me 2')," Pharrell Williams

3. "Talk Dirty," Jason Derulo, featuring 2 Chainz

4. "Let Her Go," Passenger

5. "Say Something," Christina Aguilera, A Great Big World