Beyonce sings for Obamas' first dance

Beyonce: proud, one suspects.

What a few months for Beyonce: first she gets to duet with Alexandra Burke on the X Factor, and last night she sang as Barack and Michelle Obama had their first dance as America's First Couple.

At Last was the number chosen - a song Beyonce recently sang when she played Etta James in the film Cadillac Records - and the former Destiny's Child star looked genuinely overwhelmed as she finished her performance.

But don't just take our word for it - check out the clip below.