Sia debuted an emotionally-charged music video today for her new single “The Greatest.” The video brought back Sia’s protégé Maddie Ziegler, who has appeared in other Sia videos including “Chandelier” and “Elastic Heart.” The singer-songwriter also teamed up with rapper Kendrick Lamar, who can be heard on the full track.

The video, directed by Sia and Daniel Askill, features 49 young dancers who, led by Ziegler, seek freedom from a cage. According to NPR Music, “While the song builds and soars, celebrating inner strength, the video makes a haunting shift in tone in the final minute that suggests the salvation the children fought to attain was all a cruel dream.”

According to Paste Magazine, the 49 dancers represent the 49 people that were killed in the Pulse nightclub shooting in Orlando. Ziegler dons a black wig, swapping out her signature platinum blonde, and also covers her face in rainbow tears to commemorate those who were lost.

The single is the first new song since Sia’s “This Is Acting” was released in January.

Watch Sia’s Music Video for “The Greatest”

In the months since the Pulse nightclub shooting, celebrities have participated in numerous campaigns to pay tribute to the victims. The Human Rights Campaign released a powerful video titled “Stop the Hate: 49 Celebrities Honor 49 Victims of Orlando Tragedy in Ryan Murphy-Produced Tribute.” Participants included Lady Gaga, Jane Fonda, Kerry Washington, Gerard Butler, Darren Criss and more.

Broadway for Orlando delivered a moving remake of “What the World Needs Now Is Love,” bringing together members of the Broadway community to honor the victims. Broadway legends Lin-Manuel Miranda, Idina Menzel, Audra McDonald, Brian Stokes Mitchell, among others, participated. The group also paid tribute by performing the song at the Democratic National Convention this year.

Forty-nine people were killed and 53 were injured in the Orlando shooting that occurred in June.

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