Beyoncé let loose with sister Solange Knowles, dancing at the afterparty for the premiere of her HBO documentary, “Life is But a Dream.”

While at the fine arts auction house Christies, Solange, who often DJs at private events, spun records for the audience, and Rubin Singer took a video of Beyoncé joining her sister as the New Orleans Bounce song  "Get It Ready" played.   

Singer designed Beyoncé’s Super Bowl outfit as well as the costumes of all of her dancers for the big night. 

Beyoncé was also wearing her husband, Jay-Z’s, tie around her neck as she danced with her sister.

Meanwhile, the documentary, which airs Feb. 16 at 9 p.m., promises to reveal a much more personal side of Beyoncé than fans have seen in the past.

“Everybody knows Beyoncé's music, but few know Beyoncé the person. 

Along with electrifying footage of Beyoncé onstage, this unique special looks beyond the glamor to reveal a vibrant, vulnerable, unforgettable woman,” President of HBO Programming Michael Lombardo said in a statement about “Life is But a Dream.”

Beyoncé walked the red carpet wearing a detailed Elie Saab sparkly gown that revealed most of her chest and back. She also wore minimal makeup, showing off her natural beauty.

  Beyonce Beyoncé attends the New York premiere of her new HBO documentary, "Life is But a Dream." Photo: Reuters

At the premiere, the 31-year-old spoke about her 1-year-old daughter, Blue Ivy, who inspired her to create the documentary.

“I hope that she will see all of the beautiful times [and] all the tough times that led up to her being here. 

I'm hoping that ... it can comfort her and inspire her in her life when she needs it. I felt like it was time for me to share my story because I've been through so much and I have so much to celebrate, so much to share,” Beyoncé said.

“There is something really powerful and liberating and freeing. I feel free. I feel like I've been able to heal from a lot of things because of this film and editing this film. 

And I've learned so much about myself, having to watch hours of footage of my life and my mistakes and things I did right and it just really has been an incredible learning experience.”