A cathedral service, a minute’s silence and a sing-along vigil will mark the first anniversary of the Manchester Arena attack.
Twenty-two people were killed and hundreds injured when Salman Abedi detonated a bomb at the end of an Ariana Grande concert on 22 May 2017.
Prime Minister Theresa May and Prince William will attend the memorial service at Manchester Cathedral.
The national minute’s silence will start at 14:30 BST.
The Duke of Cambridge and Mrs May will join families of victims and emergency workers who went to their aid.
Only those with invitations can attend, but people will be able to watch the service on a big screen in the nearby cathedral gardens, and further afield at York Minster, Liverpool Metropolitan Cathedral and Glasgow Cathedral.
Vigil and sing-along
The Manchester Together With One Voice event takes place between 19:00 and 21:00 and will bring together choirs from the city and beyond.
The final half hour will be a sing-along broadcast live on BBC Radio Manchester.
Families of the 22 people killed were invited to select lyrics, and members of the public were asked to make suggestions online.
Manchester City Council leader Sir Richard Leese said music was “in Manchester’s soul”, as was shown in the aftermath of the attack when “spontaneous song captured the city’s spirit”.
A crowd sang Don’t Look Back In Anger by Oasis at a vigil following the attack.
He said: “Coming together in song will once again demonstrate that remarkable sense of togetherness.”
Moment of explosion
At 22:31 bells across the city centre will ring out to mark the moment of the explosion.
Bells at Manchester Town Hall, St Ann’s Church and St Mary’s Roman Catholic Church will sound in tribute to the victims.
A further event, named There Is A Light, will run between Tuesday and Saturday with song lyrics projected on to St Ann’s Church and other parts of St Ann’s Square.
St Ann’s Square became a focal point for tributes in the wake of the bombing, with many thousands of wreaths left by well-wishers.
Some of the flowers were later composted and the soil used for the Trees of Hope Trail, where trees were planted around the city centre.
Members of the public can write messages on special tags to be attached to the Japanese maple trees until Tuesday evening.