When 12 -year-old Jakob from Stirling steps onstage in Caracas to play the pipes during a medley of Scottish folk songs, the audience can barely contain their emotions.
The children onstage have rehearsed solidly for four days. The Scottish children - 52 of them from Stirling's Big Noise Orchestra - travelled 5000 miles to get here.
Many of the Venezuelan children come from the poorest areas of Caracas and they and their families have to get home before dark. Few people venture out after nightfall in a city which has the dubious reputation of being the most violent in Latin America.
All of which adds to the emotion - and the feeling that we've all just witnessed something very special. Big Noise is the first orchestra set up by Sistema Scotland almost six years ago.
They have two more in the pipeline. All are inspired by a much older scheme - El Sistema - which was set up in Venezuela in 1975. The children they've been rehearsing and performing with in Caracas are among two million who've come through the system since.
Some, like the conductor Gustavo Dudamel, have become professional musicians but that's not the point of El Sistema. This is a social programme, not a musical one. Its aim is to raise the aspirations of children in some of the most impoverished area. Musical ability is a bonus. A better measure is a boost to confidence, improved behaviour and the discipline of being part of an orchestra. According to a survey in 2011, the Raploch area of Stirling reported all three.
What interested me when I followed the children on their trip was how much of that boost was down to music and how much was the result of a £120 million investment in the community?
Research has long suggested that music - and in particular classical music - can have huge benefits for learning. Yet one of the key theories I'd heard about - the Mozart Effect - is, according to music psychologist Vicky Williamson, a myth.
She says it's made its way into pop psychology legend as a quick fix for a complex question. If you expose your child to Mozart's music, he or she will be smarter. Yet under closer examination, the same was true of Schubert, or the recorded words of Stephen King. It didn't matter what they listened to, it was the fact they liked listening.
Where benefits were found, it was in being part of an orchestra - and working intensively as a team. The discipline of being in an orchestra helps children cope with all sorts of academic situations in which they may have to focus in on what a teacher is saying in a noisy and distracting classroom.
There's no doubting the transformation of individuals in Raploch. Ten of the musicians are now in the National Youth Orchestra of Scotland. Several receive extra tuition at the Royal Conservatoire. Since they returned from Caracas, all 52 musicians have been lobbying for extra rehearsals. They realise the children they worked with in Venezuela are good musicians because they rehearse longer and more often. Now they want to do the same. It's also raised their aspirations. Most had never been out of Scotland before the Big Trip. Now, they all want to travel.
But what of the wider community? Raploch is tiny - just 2700 folk. Almost everyone in the area is connected to the orchestra and they're enormously proud of what it has achieved in less than six years. Where once it was a community known for deprivation, it's now famous for music: the birthplace of Sistema Scotland - which is now rolling out new orchestras in Glasgow and Aberdeen.
Music has made a difference to this community. It's raised the ambitions of its children and given them something to feel proud about. But it will take many more years and much more research - both here and in Venezuela - to decide whether Sistema has succeeded as a social programme.
BBC Arts Correspondent Pauline McLean presents Is Music The Answer? on Radio Scotland on Sunday at 10.30am