A massed choir of protest will be taking place outside Hereford Cathedral on 8 June to coincide with the G8 meeting in Northern Ireland.
The choirs and singers are coming together as part of the IF campaign calling for government action to end global hunger.
Jess Ryan-Phillips, a pianist, and Neil Pigott, local fire station commander and founder of the Fire Choir, have stepped forward to lead the event.
They co-lead the Voice Squad and have worked with each other before on performance events, including two singing flash mobs last year.
"We are very lucky to have had two great musicians volunteer to lead the event for us and conduct the singers on the day," said Beth Williams, of Concern Universal, which is working in partnership with the Diocese of Hereford to make the event a success.
"We are also pleased that the Fire Choir signed up good and early so we had 60 or 70 singers from the word go. And obviously others have joined since."
Anni Holden from the Diocese of Hereford said: "We will be part of a trail of different events happening all over the country.
"We have lots of room as it's a big space in front of the cathedral. We want lots of local choirs and singers to take part, bring a banner telling us which choir they are and wearing their robes if that's what they normally do. We want to make a serious point in a fun way."
As they sing outside Hereford Cathedral, thousands of people will be urging G8 leaders to address the issue of hunger at a rally in London's Hyde Park.
The following weekend on the eve of the G8 meeting, activists will again gather in Belfast to maintain the pressure on leaders.
With Britain chairing the meeting, campaigners are looking to Prime Minister David Cameron to make sure the four big IFs - aid, tax, land and transparency - are addressed during the meeting.