What do Lady Gaga  and the musical Wicked have in common? They have both provided Broadway star Idina Menzel with insanely catchy songs to reinvent as her own — "Poker Face" and "Defying Gravity." In the midst of the Fashion's Night Out  crowd and excitement, Menzel and Michael Kors  came together at his flagship store on 61st Street and Madison Avenue to perform for me and countless other fans. It was the perfect combination of amazing and hilarious. Kors kept up as Menzel belted out those famous top notes of the Wicked finale. It was one of those duets that made me want to dance, smile, sing, and shop all at once. Too bad it only lasted for a couple of tunes. As a consolation prize, I got a close-up glimpse of Michael Kors with his famous aviator shades and spotted Menzel and hubby Taye Diggs  taking pictures with fans outside. Now, that's what I call a collaboration! Check it out.