In a small office in Glasgow, sometime in the mid-1990s, a plot was hatched to raise a bit of money for a good cause and celebrate the best of Scottish music.

But yet another fundraising lunch of sitting around, eating, drinking and a raffle for prizes no-one really wanted, didn’t quite cut it.

“I’d been involved in the music business for a long time, and I wanted to give something back,” recalls music promotor and Glasgow club owner Donald MacLeod. “So I came up with the idea of a music awards which we could call the Tartan Clefs.

“I thought we’d give the winners a quaich and raise a bit of money for music therapy. To be honest, I didn’t realise what I was getting into.”

Tonight MacLeod will join around 1000 guests at the SEC in Glasgow for the 20th SSE Scottish Music Awards, the annual celebration of tartan-trimmed pop and rock music that has become a key feature of the nation’s musical calendar.

From tiny beginnings – the first awards ceremonies were held in Glasgow’s City Chambers with no live performances and just a handful of well-oiled guests – it mushroomed to provide a stage for a who’s who of Scottish talent, from 70s’ pop legends the Bay City Rollers to the high energy of The Snuts, Lulu to Amy Macdonald.

At the same time, the awards have boosted what was a tiny Scottish music therapy charity with just three therapists, to help create a national service that uses sound, rhythm, song and melody to bring pleasure and a means of communication to people in the grip of a range of physical and mental conditions.

Indeed, just as the awards have ballooned over two decades, so has Nordoff Robbins Scotland. From its original small base in Roslin, East Lothian, and with a trio of therapists on its books, thanks in part to funds raised by the Tartan Clef awards, it now has 14 fully-trained music therapists who deliver more than 5000 sessions to people aged from one to 100 around central Scotland, in schools, community settings and at centres in Glasgow, Edinburgh, Dundee and Fife.

It’s a success story that still leaves MacLeod, owner of Glasgow’s Garage and Cathouse music venues and whose CPL Entertainment Group has promoted extravaganzas at Braehead and Hampden, a little surprised.

“There were just 100 people at the first awards,” he remembers. “We were at the City Chambers for a couple of years but I think we were all too drunk and a bit too rock and roll for that venue.

“Besides, the awards had started to grow. We moved up to holding it in hotel rooms, more artists started to get involved. The first year we had a live performer – a guy played the piano but I can’t remember who it was – we left enthused, convinced we could grow this even more.”

The Scottish live music scene was flourishing too, led by T in the Park and King Tut’s Wah Wah Hut while acts like Franz Ferdinand, The Fratellis and The View were on the rise and favourites like Annie Lennox and Wet Wet Wet were still pulling in the crowds.

The awards became established at The Old Fruitmarket, where one year Paolo Nutini sang and danced on MacLeod’s table and in the year of the Homecoming, Donnie Mclean led the crowd in a tear-stained version of Caledonia, assisted by dozens of bottles of whisky distributed among the tables.

“One year Joe Elliot of Def Leppard came and sang some Alex Harvey numbers,” remembers MacLeod, whose ‘wish list’ for future performers includes The Proclaimers, Rod Stewart and Churches and return appearances from Annie Lennox and Franz Ferdinand.

Mary Brown, music services manager with charity Nordoff Robbins Scotland recalls her favourite moment. “Hearing Jimmy Somerville singing was a real ‘stick out’ moment and a personal favourite,” she says.

“But what people don’t see is what the artists often do behind the scenes.

“When someone like Marti Pellow or Amy Macdonald, with all their experience and talent, go to visit a therapy session to see what goes on, well, it’s something we just can’t buy.”

She says artists are keen to share their passion for music and see the real benefits it brings to people facing a range of communication problems, mental and physical disabilities, she adds.

“People come to us with all sorts of issues; autism, dementia, mental illness. The underlying premise is that music can make a difference.

“A lot of people who come are very isolated, they can’t speak or find the words to say what they want. And music can help them.”

Previous years have seen Lifetime Achievement awards for – among others - Orange Juice and Simple Minds. This year Annie Lennox and Susan Boyle will join the ranks of Scotland's greatest artists in being awarded the Scottish Music Hall of Fame Award,

Frightened Rabbit scooped Best Live Band in 2011 and will return to the awards tonight for a shot at the Song Writing Award. Other nominees include Irish trio The Script, in the running for Best International Artist, and Dundonian singer songwriter Gary Clark for the Music Business Award.

Guests will be treated to performances by some of the country’s biggest stars, with guitar legend Mark Knopfler, Snow Patrol, Susan Boyle, Amy Macdonald, Tom Grennan, Kyle Falconer and The Snuts all schedule to appear.

MacLeod, now Chairman of the Fundraising Committee for Nordoff Robbins Scotland, said the awards have far exceeded any expectations from those early days.

“We’ve gone from something quite small to an event that will see over 1000 people celebrate modern music and helped people through music therapy.

“I think we can be happy with that.”