In the shadow of Stirling Castle, it's almost time for Raploch's Big Noise Orchestra to start rehearsal, and they can't get enough of it.

"Miss, please can we skip our break and snack so that we can go to orchestra straight away and practice more?" they beg.

Welcome to Raploch's revolution. An area famous for low educational achievement, lack of opportunity and high unemployment is turning itself around, and doing it through the medium of music.

Right now at the Big Noise centre, excitement is at fever pitch. In order to show their support and give a huge boost to the pilot Scottish project, world-famous conductor Gustavo Dudamel and the Simon Bolivar Youth Orchestra – are on their way to Raploch.

These Venezuelan celebrities are the global ambassadors for the magic of their El Sistema method. They are also a musical phenomenon in their own right. This visit is the musical equivalent of David Beckham and some of his famous mates coming to your neighbourhood to play with your school team.

El Sistema is a musical education method that is also a philosophy of social transformation. It has been established in the poorest parts of Venezuela for more than 35 years, but has recently spread its influence globally. Governments, musicians and social reformers across the world are all taking a keen interest.

At the initiative of Edinburgh's Richard Holloway, former chair of the Scottish Arts Council, an El Sistema off-shoot was transplanted in Scotland and has been growing under the name of Big Noise since 2008. Concentrating on group learning and the immersive musical experience of playing together in orchestras, it aims "to foster confidence, teamwork, pride and aspiration" in its students.

The centrepiece of Dudamel's morale-boosting visit is The Big Concert on June 21, midsummer night. This will feature the Bolivar band and their maestro performing on an outdoor stage against the backdrop of Stirling Castle.

The international pros will play side by side with the Raploch kids, buddying them through the concert programme. First Dudamel will conduct the Big Noise orchestra by itself, playing a Purcell Rondo. Then the Scottish children will sit in with the Bolivar orchestra as they play Beethoven's Egmont Overture together. After that, the Bolivars will let rip with Beethoven's Eroica Symphony.

Scotland's The Big Concert is part of the London 2012 Olympic Festival. Managed by Unique Events, you can get tickets to join the rest of the 8000-strong audience on site, or listen to it broadcast live on BBC Radio 4. If you're out of town, you might find yourself near one of the 22 large screens around the UK that will be relaying it. You can also buy tickets to watch the concert relay in Japan, New Zealand, Kenya, Germany, France, Spain, Denmark, Sweden, the US, Canada and Ireland. Are you getting the impression that this is a big deal?

But the children of Raploch will have even more, because the Venezuelan superstars will stay in Raploch for four days. Their Big Visit aims to leave an enduring artistic and inspirational legacy in the area. To this end the Bolivars will also play at the high school, the community centre, with Raploch's adult orchestra, and even in the homes of people around the estate. The Big Noise children will get to "Take a Venezuelan Home for Tea", and have them play to their families in their own front room.

So what are the locals likely to make of all this international attention?

"I expect the kids will be simply gobsmacked," says Fergus McWilliam, a Scottish French horn player, member of the Berlin Philharmonic Orchestra, and now one of the musical advisers to the board of the Big Noise project. "I can't imagine how anybody could be prepared for a force of nature like the Bolivars: you can hear their jaws hitting the floor."

"It's very important that the local community realise this event is not just for other people to enjoy," says Big Noise percussion tutor Iain Sandilands. "It's actually for them, and it belongs to them." And so, not content with relying on LED screens and flyers, the Big Noise team have been knocking on doors across Raploch, speaking to local families to encourage their interest, and ensure they get access to tickets. After all, this is a grassroots social project at heart and to succeed it needs to stay that way.

But Beethoven's Egmont is not an easy piece. Are these children, many still beginners on their instruments, going to be able to manage, especially in the spotlight? Even McWilliam describes Egmont as a piece for which he has "to count like crazy, even in the Berlin Phil".

In fact the parts have been simplified for the Big Noise beginners. But Ali Gornall, double bass tutor at Big Noise, admits that the challenge remains. Some of the pupils, she says, "are quite tired" from the work, "but they're learning what it is to prepare for something big, important and challenging. They've actually been very stimulated by the repertoire, and they all really love it. That's spurring them on".

"Some of our pupils are dealing with tough personal circumstances," explains Sandilands. "We're coping with low self-esteem and lack of self-confidence," so the challenge is not just to teach instrumental technique.

In his percussion department, being bold enough to play something like the cymbals "takes courage".

One boy has been turning to his teacher in rehearsal, saying: "I cannae do it, I cannae do it." But everything changed last week, when "with enormous encouragement, he realised how important his role is in the orchestra".

"The main thing is that every child can share the experience, whether it's a cellist just playing along on open strings, or a violinist playing all the notes of Egmont," concludes Sandilands.

McWilliam elaborates: "The real point of The Big Concert is that how one instrumentalist plays Egmont is just the tip of the iceberg. This is actually about social transformation." Then he adds cheerfully: "But you're going to get some great music anyway."

The Big Concert is in Raploch, Stirling, on June 21 at 7.45pm.