A group of 30 men and women, many recovering from serious and life-threatening addiction to drugs and alcohol, stand in a semi-circle - the stress drawn from their conditions visible on some of their faces.
And then, in unison, they begin to sing.
"If I had the wings of a dove," they vocalise using several layers of harmony as the choir leader snaps her fingers to the rhythm.
"Wings that would take me where I want to go. I'd fly to the utmost, way out into space."
This is the
Raucous Caucus Recovery Chorus
- a choir run by the charity Action on Addiction whose patron the Duchess of Cambridge is visiting on Tuesday.
Choir leader Wibke Hott
Members of the group are in recovery from different forms of addiction according to Jacquie Johnston-Lynch, the charity's head of service in Merseyside.
"That will be recovery from drugs and alcohol addiction or it might be recovery from gambling addiction or an eating disorder," she explains.
"Family members also come along as well and take part."
The choir is based in a non-residential centre which sees members put through a 48 day recovery programme.
The treatment is described as "abstinence based" meaning users aim to become completely free from the substance to which they are addicted.
Choir members are expected to have been sober for at least 24 hours before rehearsals.
People in need
Despite its unusual nature as a form of treatment, Ms Johnston-Lynch says the choir has been successful: "Most people would say people need to be doing group therapy, they need to be doing counselling."
"But you'll notice a lot of the guys saying that they didn't really feel that they belonged anywhere."
"Taking part in a choir they begin to understand all about communities just through singing."
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