Zoe Unsworth finished the night off with a couple of songs including Oasis' Don't Look Back in Anger, which acted as a symbol of unity in Manchester after the terrorist attack previous year.
The Parrs Wood High School's Harmony Group were among the acts that performed during the Manchester Together - With One Voice tribute concert in Albert Square, staged to mark the first anniversary of the terrorist attack at the Manchester Arena, which cost 22 Grande fans their lives on 22 May, 2017.
Grande tweeted a tribute to the victims and survivors.
"Thinking of you all today and every day", the singer wrote early Tuesday morning.
The finale was a mass 30-minute communal singalong including Don't Look Back In Anger by Oasis, One Day Like This by Elbow, Ariana Grande's One Last Time, Never Forget by Take That and The Beatles' All You Need Is Love.
"Today my thoughts and prayers are with those who were lost on that bad night, their loved ones who have so bravely battled to rebuild their lives; those who have courageously fought to overcome physical injury or mental scars; our first responders and emergency services and those volunteers and professionals who are continuing to help this community heal", May wrote.
Shaun Ryder, of the Happy Mondays, said: 'I am thinking of you.
"All of you - and many more in this great city - are the very best of what this country stands for".
Manchester is marking the day with a series of events including the memorial service at the cathedral and a musical tribute in the evening.
Greater Manchester Mayor Andy Burnham said it was a day to "come together".
The service, attended by first responders, civic leaders and some of the scores injured in the bombing, led the minute of silence at 2.30pm (2330 AEST), which was also marked at British government buildings nationwide.
Some laid bouquets of flowers in St. Ann's Square. Meanwhile the Duke of Cambridge gave a reading and met some of the bereaved families.
And at At 10.31pm, bells will ring out from the city's Town Hall, St Ann's Church and St Mary's RC Church to mark the moment when the attack took place 12 months ago.