It was the most emotional moment for those in the Oscar audience: Lady Gaga’s intense performance of Diane Warren’s song “Til It Happens to You” from the film The Hunting Ground. (Watch above) The audience at the Dolby Theatre was visibly moved by the performance, some — like Best Actress winner Brie Larson — seen weeping as the performance ended. And it can’t be denied that the moment — particularly what it symbolized for the fight against sexual assault — was effective.

Beginning on a simple darkened stage, Gaga sat behind a white piano dressed in a matching white dress. But as the song (and Gaga’s voice) crescendoed, she was joined onstage by dozens of survivors of sexual assault who stood still, arm in arm, behind her. It helped of course that the performance was introduced — and the audience primed — by none other than Vice President Joe Biden, who used the occasion to call for people to join in the White House’s anti-sexual assault campaign It’s On Us.

Nonetheless, Gaga delivered an energetic, emotional rendition of the song, even if — at least according to some fans on social media — it sounded off-key to some. That might have been a technical matter, however; Adele’s performance at the 2016 Grammys was for many viewers similarly off-key, a problem the singer attributed to bad placement of a mic cord. Notably, a piano factored into that performance as well.