They included the Manchester Survivors Choir, made up of people who were at the arena on the night of the fateful concert last May 22, and Parrs Wood High School's Harmony Group, whose post-attack tribute went viral past year.
So, it seems fitting the crowd remembered the tragic day with music. Grande suspended her Dangerous Woman Tour after the bombing and returned for the One Love Manchester charity concert weeks later, which raised funds for victims of the attack.
Bells on the city hall and churches rang out at 10:31 p.m., a year since the bomb exploded.
"It was created to strike at the heart of our values and our way of life in one of our most vibrant cities, with the aim of breaking our resolve and dividing us". A clip went viral, prompting both Gallagher brothers to donate all future royalties from the song to the We Love Manchester fund, which now stands at £21m.
Grande, who had just finished performing when the bomber struck outside, also shared a message of support for those affected.
"I love you with all of me and am sending you all of the light and warmth I have to offer on this challenging day", she wrote in a tweet that included a bee, the civic symbol of Manchester.
Tributes were also made by the city's two Premier League football clubs, City and United, with Manchester United saying: "Always Remember". I am proud to be a Mancunian.
Young women pay their respects in St Annes Square on the 1st anniversary of the Manchester Arena bombing in Manchester.
Twitter REACTION The 53-year-old said he was'delighted with the reception as it united the crowd
Manchester Storm ice hockey team also announced on Tuesday they are retiring their number 22 jersey in honour of the victims.
The Prince and May were among the congregation at a packed Manchester Cathedral where a special service was held to remember the victims of what was one of worst bomb attacks on the British mainland since World War II.
Later, thousands of people - including a choir of survivors - are due to gather for a concert and sing-song in St. Ann's Square.
Later in the day, more than 3,000 singers from local choirs, including a group who were at the arena on the night, are expected to join forces at a "Manchester together" event in the city with half an hour of communal singing.
"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.
"We were very lucky, we know how lucky we are", he told Sky News.
"With Manchester, you kick one of us, you kick all of us, and we'll all get up, and we'll all start fighting again". "The Manchester Arena attack showed the worst of humanity", said Ariana Grande as she spoke in detail for the first time about last year's bombing.