ASK Clare Grogan if she can choose between acting and singing and her response is emphatic. “Absolutely not. It’s all swings and roundabouts. I go through phases where I will do a lot of music, but then there will be a period where I am doing radio or TV work. When I was younger I wasn’t geared more towards acting or singing: I just wanted to perform.”

Her platform to perform came when Grogan was fresh out of Notre Dame High School for Girls in Glasgow, winning the part of Susan in Gregory’s Girl in the same year that her band Altered Images were signed to Epic Records.

“I call it my double whammy. I think when you are young you almost accept extraordinary things. You think: ‘Yes, I did quite fancy being a film star and the lead singer in a successful band’. It is only years later that I look back on it and actually realise that it was remarkable.”

For now, it is music that is the focus for Grogan as she prepares to perform at Sandfest, a one-night-only festival at Glasgow’s Royal Concert Hall. The event features some of Scotland’s best known 1980s' artists – The Bluebells, Justin Currie and James Grant – but is also raising money for Down’s Syndrome Scotland, an issue close to Grogan’s heart.

Her niece Matilda, the 14-year-old daughter of Sandfest organiser Douglas MacIntyre, has Down’s Syndrome.

“I have always felt very connected to the issues surrounding Down’s Syndrome because of having Matilda in my life. She’s very determined, which is an amazing thing, and she’s funny, cheeky and just great fun to be around. One afternoon, when she didn’t have her own mobile phone, she asked to borrow mine to look at the photographs on it. Then for about six months afterwards, I kept running into people who told me they had had a lovely chat with my niece Matilda. So while I was oblivious, she had been going through my phonebook calling up everyone I knew for a natter! She loves performing too, so she will be up on stage at Sandfest doing her stuff as part of the Ups and Downs Theatre Group choir.”

“I think there are a lot of charities that get a lot of attention – and they are deserving of that – but some charities also get a little bit overlooked and Down’s Syndrome Scotland has possibly been one of them. Sandfest will hopefully be an amazing opportunity to raise its profile.”

Grogan is clearly excited to be back on the stage, especially for such a worthwhile cause. After an 18-year break from singing to “concentrate on other things”, she “ran out of excuses not to sing” and began playing gigs again with a group of female musicians.

“I think if you have ever been in a band, and you love music and you love to sing, you can’t help yourself and you get totally drawn in again.”

Grogan still remembers attending her first concert, seeing the Bay City Rollers in the Glasgow Apollo with her sister Margaret.

“I was just so excited that a Scottish band had that much success. It made me feel like there was a chance, a chance that you could come from Scotland and have that kind of career.”

It wasn’t long after that before she was performing, playing with Altered Images across the bars of Glasgow. “I think the first gig I played was the Mars Bar, a tiny venue off St Enoch Square. It was one of the centres of the post-punk scene along with the Bungalow Bar in Paisley and the Doune Castle in Shawlands: those were where all our early gigs took place. Mostly I loved the idea of just being on a stage and getting the chance to be part of something.”

When mainstream success followed, Grogan’s parents struggled to keep up with her high-flying lifestyle – ending up having to buy the NME every week to find out what she was up to.

Yet no matter how far from home she went, Glasgow always remained firmly in her thoughts. Even now, living in London, she is “always coming back and forwards."

She says: "A lot of my family are in Glasgow and I am always up doing little bits and pieces of work. I’m in Scotland every month – I’m not away long enough to miss it.”

Her set for Sandfest is sure to satisfy fans looking for nostalgic pleasure, and she is promising to “give people the hits.”

She says: “I always like throwing in an occasional song that’s not necessarily mine – although I haven’t decided what that will be yet – but I will also perform the classics. I will play our first ever song Dead Pop Stars, which I don’t always get the chance to do, but it’s become such a favourite to play and perform.”

“It’s quite strange that people are so enthusiastic about the music, but that’s very infectious. Yes, there’s huge nostalgia attached to it, but also a lot of artists from the eighties are making new music and having chart success. I look out at these shows and see a lot of young people there as well – people seem to love eighties music.

"I was excited to see that the trailer for the new film Lady Bird used one of my songs. It’s lovely, it’s just a really nice nod that after all these years people still relate to the music.”

The popular enthusiasm for eighties music is clearly shared by Grogan, and she is relishing the chance to watch her old musical cohorts performing at Sandfest.

“It’s going to be really nice because apart from anything else I haven’t seen a lot of these people in a long time. It’s going to be like a bizarre school reunion: friends reunited but with an audience. I think we are all performing together at the end for a finale, which will be great.”

Now a mother to 13-year-old Ellie, Grogan admits that being a parent can affect the decisions she makes in her career.

“I’m not exactly going to turn down the opportunity of a lifetime, but as a mum I have to remember that I can’t be in two places at once. With a lot of jobs, you have to be away for a while, so I try and avoid them because it just doesn’t work for me. But that will all change once Ellie gets to the age – as teenagers do –where she decides she doesn’t want to know me.”

But, not quite a grumpy teenager yet, Ellie has been happy to join her mother on stage at a few gigs. Sandfest is also likely to be a family affair, with both Ellie and Grogan’s husband Stephen (who was originally in the band) hoping to join her on stage.

“My other nieces Amelia and Poppy might perform with me too – we are a bit like the Von Trapps.”

Sandfest is now in its 10th year after beginning in MacIntyre’s garden in the South Lanarkshire village of Sandford. After moving to a village hall and then growing each year, the family is delighted to see it now being held in the 2,000-seat Concert Hall.

“My brother-in-law, Matilda’s dad, has been championing this event for years and years. I’ve never done anything quite like it and I think it would be great to keep it going – we just want to get as much support as possible.

“Our family has been brought up to have a very accepting and understanding view of things, but when it becomes personalised then I think things do change.

"You look at other people and the way they respond to somebody like Matilda – and you notice it more. You end up feeling very protective of that person because you can see that not everybody responds the way you would want them to.

“I think all of us in society need to just treat people as people – accept others and see them as a person and not a condition.”

Sandfest is on March 18 at Glasgow’s Royal Concert Hall from 7.15pm. See for tickets