The #1 song on May 21, 2009

Boom Boom Pow By The Black Eyed Peas

Other #1 songs on May 21, 2009

UK #1 Song

Boom Boom Pow
The Black Eyed Peas

#1 R&B Song

Blame It
Jamie Foxx featuring T-Pain

#1 Country Song

It Happens
Sugarland

#1 Alternative Hit

Know Your Enemy
Green Day

#1 Dance Track

Halo
Beyoncé