A minute's silence will mark the first anniversary of the Manchester Arena attack, the government has announced.
Twenty-two people were killed and hundreds injured when Salman Abedi detonated a home-made bomb at the end of an Ariana Grande concert on 22 May.
All government buildings will observe the minute's silence at 14:30 BST on 22 May. Other organisations may follow suit, the government said.
A service at Manchester Cathedral and a communal sing-along are also planned.
The Manchester Together - With One Voice event will take place on the same day and bring together choirs from the city and beyond.
The final half hour will be a sing-along broadcast live on BBC Radio Manchester.
A second event, named There Is A Light, will take place 22-26 May. Song lyrics will be projected on to St Ann's Church and other parts of St Ann's Square.
The memorial service at Manchester Cathedral will be before an invited congregation.
It will be screened in Cathedral Gardens for the public as well as at York Minster, Liverpool Metropolitan Cathedral and Glasgow Cathedral.
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 broke into a rendition of Don't Look Back In Anger by Oasis at a vigil after the attack.
"Coming together in song will once again demonstrate that remarkable sense of togetherness," he said.
"It is a fitting way for us to honour those who went full of joy to a music concert but never came back, or saw their lives changed forever."