On Wednesday night Beyonce Knowles performed at the White House, where the President Obama was entertaining the President of Mexico Felip Calderon.

The singer wore a bespoke gown created by design duo Ralph & Russo.

Her tulle corseted silk gown, encrusted with over 20,000 hand sewn gunmetal grey Swarovski, crystals was finished with crystal drops, a thigh high slit and heavily encrusted train.

You won’t be surprised to learn that the gown took 3 months to create.

It’s a shame we can’t see the whole look.

Love the dress, really don’t like the colour of her hair.

Credit: Sketch provided by Ralph and Russo & Getty