The US singer arranged the One Love Manchester fundraising gig in the wake of the attack, which took place at her concert at Manchester Arena on 22 May.
22 people were killed and many more injured when a suicide bomber detonated a nail bomb at the venue.
Ahead of Ariana’s defiant first performance of ‘Be Alright’ and ‘Break Free’, Scooter appeared on stage to say a few words in tribute to those who lost their lives.
“From my friend Ariana Grande and the entire Dangerous Woman crew, myself and the rest of us around the world are so grateful to you for stepping up and taking action,” he told the crowd at the Emirates Old Trafford cricket ground.
“We also want to thank the Manchester first responders and the bystanders who are probably here tonight and risked their lives to save others. Please give a round of applause to them.
“Last night this nation was challenged, and this nation had to make a decision about whether to come out here tonight, and this is so beautiful. You guys made that decision, you looked fear right in the face and said, we are Manchester and the world is watching.”
Scooter also delivered a message from 15-year-old Adam, who is currently recovering in hospital and lost his friend Olivia in the bombing. “Don’t go forward in anger, love spreads,” he said.
Scooter added: “Hatred will never win, fear will never divide us, because tonight we stood with Manchester.”
Other acts performing include Justin Bieber, Coldplay, Katy Perry, Miley Cyrus, Robbie Williams and Little Mix.
All net ticket proceeds will go towards the We Love Manchester Emergency Fund set up by Manchester City Council in partnership with the British Red Cross.
To donate £5 to the We Love Manchester fund, text LOVE to 70507. Texts cost £5 plus your standard network rate, with 100% of your donation going to the We Love Manchester fund.