Billie Eilish performed at this year's Lollapalooza.

Billie Eilish performed 'What Was I Made For?'' live for the first time during her headlining performance at Chicago's Lollapalooza music festival on Thursday, August 3.

The 21-year-old singer co-wrote the poignant ballad with her brother Finneas for the soundtrack of the movie "Barbie" at the request of director Greta Gerwig and music producer Mark Ronson.

Billie Eilish took the Lollapalooza stage in a black Michael Jordan Chicago Bulls jersey and basketball shorts.

For 'What Was I Made For?', Billie Eilish sat on the edge of the stage while the music video for the song played on the screen behind her.

As she performed the emotional ballad, the audience cheered her on. When Billie Eilish reached the final verses, she smiled and looked back at the final scene of the music video.

What Was I Made For? by Billie Eilish is included on 'Barbie The Album', which debuted at No. 2 on the Billboard 200.

Following its release, 'What Was I Made For?' debuted in the Top 20 of the Billboard Hot 100.

At the same time, "What Was I Made For?" won the No. 1 in Australia, giving Billie Eilish her second local ARIA Chart debut after 'Bad Guy'.

In an innovative move, the production of Billie Eilish's performance at Lollapalooza relied on solar power from smart, zero-emission battery systems.

The initiative is a project of the Music Decarbonization Project, which was co-founded by Billie Eilish herself in collaboration with environmental non-profit organization REVERB.

The zero-emission battery systems that provided the energy required for Billie Eilish's performance were charged via a temporary solar farm.

The use of these battery systems has been a powerful demonstration of clean energy technologies that can drastically reduce the live music industry's greenhouse gas pollution and accelerate the transition away from fossil fuels.