Pop star Ariana Grande took the stage in Manchester Sunday night, less than 24 hours after a deadly terror attack in London, and less than two weeks after an explosion ripped through the concert venue where she performed, killing 22 fans and injuring more than 100.

Donning ripped jeans and a white "One Love Manchester" sweater, the singer started upbeat as much of the young crowd - estimated to be at least 60,000 strong - appeared both excited and overwhelmed, declaring her love for the still mourning city.

Part way through the concert, Grande thanked the crowd for their "love and unity," noting that it is "the medicine the world needs right now." She also acknowledged that they had an entirely different show planned but changed much of it the previous day after her meeting with the mother of slain 15-year-old victim, Olivia Campbell.

"She told me Olivia wouldn't want me to cry," Grande said. "And she would have wanted to hear the hits."

But it wasn't just Grande paying her respects to the city and its victims.

Highlights of the "One Love Manchester" benefit included Grande joined by the Black Eyed Peas, performing their 2003 hit "Where Is the Love?" which directly addressed the buregoning threat of terrorism in its lyrics, and advocated a message of "one love." Some 14 years later, frontman will.i.am urged the packed crowd to raise a hand in solidarity.

Longtime friends Grande and Miley Cyrus also performed the Crowded House hit "Don't Dream it's Over," and Katy Perry - following an address insisting that "love conquers hate" - sang "Part of Me." Justin Bieber's performance too was met with enthusiasm - complete with a glimpse of policemen dancing with children outside the stadium.

"One Love Manchester" also featured heartfelt video messages from Stevie Wonder and former soccer star David Beckham, Demi Lovato, Kings of Leon, Rita Ora and Kendall Kardashian. British girlband Little Mix, Mac Miller and a duet with Victoria Monet and Grande performing "Better Days."

Survivors also took to the stage alongside Grande to close out the concert at the Emirates Old Trafford cricket ground, paying tribute to the lives lost, with "Somewhere Over the Rainbow."

Following Saturday night's terrorist assault on London Bridge, Grande tweeted that she was “praying for London.” Earlier on Sunday, her manager Scooter Braun released a statement declaring that, "after the events last night in London, and those in Manchester just two weeks ago, we feel a sense of responsibility to honor those lost, injured, and affected."

“We plan to honor them with courage, bravery, and defiance in the face of fear. Today’s One Love Manchester benefit concert will not only continue, but will do so with greater purpose," he continued. "We must not be afraid and in tribute to all those affected here and around the world, we will bring our voices together and sing loudly."

Braun went on to say that they had the "full support" of the Greater Manchester Police and the government and are assured the safety of all those attending is the highest priority.

“All artists involved have been unwavering in their support this morning and are determined to carry on with the show. We ask the strong city of Manchester and the world to join us in making the statement that hatred and fear will never win," he added. "Today we stand together. Thank you.”

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More than 50 countries worldwide have signed up to air the show live, with BBC Worldwide affirming Sunday that those plans remained. All net ticket proceeds from the concert will benefit the "We Love Manchester Emergency Fund," created by the Manchester City Council and the British Red Cross.