A jam session is already in full swing as five musicians from the Royal Scottish National Orchestra join class 4S at Kelvin School in Glasgow to start an afternoon workshop as part of their continuing project. Within minutes the children are marshalling the players and rehearsing the musical adventure Punchinello.
It is impossible to sit quietly when surrounded by the RSNO players, led by their music animateur Paul Rissmann. They are a tidal wave of fun and encouragement.
A children's book inspired the project. Max Lucado's You Are Special tells of Punchinello, a wooden doll who is struggling to be happy in a village full of judgmental people.
Headteacher Sister Pat Gribbin believes the story reinforces something that underpins all aspects of the curriculum for the special school's 43 pupils, who are aged two to18 years and suffer from severe visual impairment and multiple disabilities.
"The basic message of this story is that every person should have a good self-esteem," she explains. "For our children that's what is very low. The story is a way of helping them develop a true self-esteem.
"If they know within themselves that they're valuable, that they're special, then it doesn't matter that they can't do a lot of things. They're loveable and everybody needs to know that they're loved."
Mr Rissmann's working methods would raise anyone's self-esteem. He lights up every room he enters and children befriend him with ease. What is his secret?
"Just being really open with the kids," he says, "fostering a sense that we are all making music together, that we're equals and have an equal role in the music making. It is not about teaching people music."
There are obvious reasons for using music as a means of telling a story for visually impaired children, but Sister Gribbin's enthusiasm for using it is based on hard evidence.
"There has been a great deal of research recently on the effect of music on the mind," she says. "The part of the brain that deals with emotions is next to the part that interprets music. That partly explains why music has such an effect on our emotional state.
"Many of our pupils are emotionally vulnerable and music is a way they can express themselves. They communicate through music in a way they can't do verbally."
She knows that in Mr Rissmann and the RSNO she has a dream team that can make that happen. "They provide a tremendous amount of enthusiasm for our pupils," says Sister Gribbin. "They bring a spark to the curriculum that sets alight the school.
"During a project like this all the school becomes involved. People pull together and there's tremendous team building."
Punchinello is Kelvin School's second big collaboration with the RSNO's education department - the first was the hugely successful Pied Piper of Hamlin project two years ago - and it was made possible by a New Opportunities Fund grant.
"This is high-calibre involvement with a national orchestra," says Margaret Orr, Glasgow City Council's senior education officer for children with special needs, as she lists the critical factors that secured the funding. "The school has a track record in looking at innovative ways to increase the children's development and in marshalling resources from a variety of sources. And this is an exercise that couldn't have been done within core curriculum time."
Mr Rissmann provided the basic structure for the show, but many of the children were quick to suggest changes. One came up with the main character's theme tune, another suggested a trumpet volley at the end of one section, while another decided to ditch his beloved accordion to provide a more meaty contribution on a didgeridoo.
The teamwork and imagination come across splendidly in the final performance. After a foot-tapping opening chorus, the nine classes take turns to provide effective musical embellishments to the basic story, punching out catchy tunes and coming close to beating the RSNO ensemble at its own game with a moody didgeridoo solo and an exuberant jazz number. Even those pupils limited to making the merest brush of a hand against chimes or hitting a wooden block are engrossed in the event.
"Thank you. You've made my day and you will always be special," said one pupil to the RSNO group at the end, accompanied by rousing applause from the audience in the packed hall. Everyone agrees that this sort of collaborative show must go on.
RSNO head of education Ewan Small, tel 0141 225 3584; e-mail firstname.lastname@example.org