A community choir in east London created partly on the advice of doctors to help patients with mental issues is performing in the BBC Proms on Sunday.
The Victoria Park Singers was set up with some members who were advised by their doctors to join.
Choral singing can help mental wellbeing, according to TV psychologist Honey Langcaster-James who has previously sung with the choir.
"Research has shown that joining a choir can reduce loneliness and improve mood," she said.
"The psychological benefits of singing with others from all walks of life can benefit mental wellbeing and is a great way to socialise, because you have an activity to focus on which can reduce social anxiety.
"I would like to see more doctors prescribing patients a good dose of choral singing."
The Victoria Park Singers are performing John Luther Adams' In The Name of the Earth at the Royal Albert Hall on Sunday at 11am, along with four leading choirs, in the mass choral work of 600 voices being broadcast live on the BBC.
Choir director Hannah Brine, who won a BBC Unsung Hero award in 2015 when she set up the choir, said: "More and more new members tell me they were advised to join by their doctors.
"There is growing awareness of the mental health benefits from being in a choir which has helped so many on a social and emotional level."
One singer that her choir has helped is 40-year-old truck driver Michael Hyatt from Bow, who had been through a family bereavement.
"My dad passed away just before Christmas," he said. "I was in a dark place, suffering crippling anxiety.
"But I found going to weekly choir practice really helped. Learning the set took my mind off of all the stuff I was going through."
The only time he really sang before was "murdering karaoke or singing along to the odd show tune in the cab of my lorry", he admits.
He often gets raised eyebrow from other motorists sitting in traffic.
"You don't often see a big hairy truck driver singing along," he smiled. "I had never sung In public before, apart from people accidentally catching me singing in the truck."
But since joining the choir he has performed to large audiences at four concerts, including his first solo, something he had never dreamed of doing, and now performing in the Proms.
Other choir members tell similar stories.
Tenor Chris Watson, who retired three years ago, had read about dementia and how keeping the mind active was likely to reduce the risk.
"I wanted a regular activity that challenges me mentally and found this community choir in my neighbourhood.
"I had never sung before and didn't read music, but three years on I have sung in public concerts and now, on Saturday, I'm singing at the Proms! My late mum would be so proud—I hope they get Radio 3 in Heaven!"
Jessica Thorn made sure she was at every rehearsal for the Proms. For her, it was "a once-in-a-lifetime experience to be a part of such fantastic music performed at the Royal Albert."
They rehearse every Wednesday evening during term time at Lauriston Primary School in South Hackney. Anyone wanting to join can sign up online at the Victoria Park Singers website.
Fifty of the 100 members take to the stage on Sunday as part of a mass choir of 600 voices, joining up with the BBC Symphony Chorus, LSO Community Choir, London International Gospel Choir and Crouch End Festival Chorus.
Adams' In The Name of the Earth which is also broadcast live on Radio 3 is a large-scale musical spectacle immersing the audience in the mass of choral sound.
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