Chicago, Illinois - Billie Eilish paid tribute to the late Angus Cloud with an emotional performance of her song from the Euphoria soundtrack at Lollapalooza.

The 21-year-old took the stage at the Chicago music festival for her headlining set on Friday night.

Eilish gave a passionate performance of Never Felt So Alone, a collaboration with Labrinth that was featured on the hit HBO drama before it was formally released in April.

The Ocean Eyes artist gave a shout-out to Cloud, who starred as Fezco on Euphoria, at the conclusion of the song.

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"RIP to Angus Cloud, everybody," she told the crowd.

The 25-year-old actor tragically passed away on July 31. His cause of death has not yet been confirmed, but his family revealed that he had been struggling with his mental health after the recent death of his father.

Along with her emotional rendition of Never Felt So Alone, Eilish also performed What Was I Made For? from the Barbie movie soundtrack for the very first time.

Eilish grew visibly emotional as she sang the song, with the accompanying music video playing on the screen behind her.

The track is featured in a poignant scene towards the end of the movie, and it has been climbing the charts since Barbie hit theaters on July 21.

Elsewhere in the headlining set, Eilish performed Happier Than Ever, bad guy, TV, you should see me in a crown, and more.