Last night fans were stunned when Beyonce Knowles and Jay-Z arrived on stage to join Alicia Keys whose “Freedom” tour was held in New York’s Madison Square Gardens last night.

Wearing a black lace Dolce & Gabbana lace bustier dress, Beyonce joined Alicia on stage to perform their new single “Put It In A Love Song” which John Galliano recently used during his Christian Dior Fall 2010 presentation.

Bey’s hubbie Jay-Z later surprised fans by joining Alicia on stage to perform their hit single “Empire State of Mind”.

Wow. Three great performers for the price of one.

Beyonce paired her dress with a ‘Sasha Fierce’ pair of Giuseppe Zanotti gladiator studded heels and silver jewels.

Blake Lively had our jaws on the floor when she wore this same dress to the ‘Sherlock Holmes’ New York Premiere last year.

Both have amazing legs to pull of this sexy look.

I love Bey when she curls her hair like this, poker straight doesn’t always work for me.

Credit: Style.com & Rex