A group of singers are standing in front of musical director Ben Jones wearing smiley face badges with a small tear rolling down the face.

The badges represent the message 'there's no them and us - there's only us', which fits well with the foundations of Harmony Choir which has been set up to look at how singing in a group can improve mental health.

Half of this 50-strong group have experienced mental health symptoms at some point in their lives, while half have no diagnosed disorder. But this fact is insignificant to the make-up of the choir.

Organiser Liesbeth Tip says the aim was always to create a sociable environment where people can enjoy singing without the usual taboos around mental health.

The University of Edinburgh project also wanted to build on existing research which has shown singing in a choir can have a positive effect on the singers' mental well-being.

For 61-year-old Trish, the discovery of singing in a choir was a pivotal moment for her.

"I sometimes say my life began at 40 because that was the turning point where I started to build up meaningful things in my life," she says. "One of them was definitely singing."

Looking back, Trish can trace her mental health symptoms back to her childhood but it wasn't until her late 20s that she was diagnosed with depression, anxiety and obsessive compulsive disorder.

The charity worker has been singing in various choirs for the past few years but wanted to sign up to the Harmony Choir when discovering she would be contributing to mental health research.

"Singing has been such a big part of managing my mental health" she says.

"I don't sing on my own at all - it is definitely about singing with other people.

"You have to think about your breathing which relaxes you a bit and you have to focus on the notes, the music and listening to other people.

"It is quite good for being in the moment."

As well as the calming effect singing in a group brings, Trish says it has also helped her to counter another area she has struggled with in her life.

"Isolation is a huge thing and it's quite difficult to make myself go out and do things," she says.

"Even with the choir, I sometimes get home and think I don't know if I can get myself there. I push myself and then I enjoy it."

Crediting people like TV choirmaster Gareth Malone for reviving the notion of community choirs free of auditions and performing pressures, Trish says the inclusive feel of this choir has been refreshing.

"I don't know who has mental health problem and who doesn't - and it doesn't matter. It is a mutual setting in that way. People are really supportive and make an effort to speak to you.

"I enjoy the learning as much as the actual performance. If you are a bit anxious, you can just come in and sit and sing.

"I still struggle but I have worked out ways of managing and coping mechanisms and ways of living - of getting something out of life even though it is not very easy day-to-day."

While the choir has been rehearsing for their debut Fringe show at the Just Festival on August 26 , Liespeth has been running weekly surveys to find out how the choir members feel after singing together at rehearsals.

The University of Edinburgh PHD student, who is a clinical psychologist by profession, has been tracking people's feelings of well-being, enjoyment and connectedness over the last eight weeks.

She says: "I just thought by putting people together into a choir that has people with mental health symptoms and people who don't necessarily have that, you can hopefully change ideas that people have.

"For the people that have mental health symptoms, they can have quite negative judgements about themselves - 'something is wrong with me', or 'I am inferior to others'.

"People can be quite isolated because of social anxiety or because of low self esteem and their illness so I thought by including everyone in the choir, where everyone is the same, I hope that changes social anxiety and self esteem.

She adds: "I'm pretty convinced the results will point to improvements in people."

Choir member Emma can already feel these changes. The 49-year-old has struggled with depression in the past and was interested in the impact of this project on a topic she feels is still very much taboo.

"Somehow it is so much easier to talk about physical illnesses," she says. "I had a big physical illness and suddenly there was all this support available and I was thinking 'I've had all these other things'.

"Singing with other people means you can lose your voice a little bit in them. So I think it is a combination of the sound the group makes and also being a part of something.

"It is getting more rewarding as we are getting more together."

Emma is now looking into continuing this new-found love of singing.

"I understand music and I can hear music but I don't really have a good range. So in a way, it is nice to be able to do it without being really good.

"It gives you a bit of confidence in terms of being a part of something.

"I look forward to the Monday evenings and it is something nice to tell people that I am in a choir. And I always feel better at the end of the sessions.

"There's already a bit of me who is saying 'aw but then it will end' so I am now looking at joining a long-term choir."