The conductor raises his left hand, clenches it and raises one determined thumb. The noise in the music studio diminishes but doesn’t stop. The conductor waits, patient, expressionless. At last it’s quiet enough and he raises his right arm and then drops it decisively. The orchestra begins: xylophones tinkle, cymbals crash, Korean blocks crack and glockenspiels tingle.

The difference is that this conductor is six years old, the music his peers are playing is his own composition, and pinned up behind him is the score he wrote in his own graphic notation. What’s also different is that these five- and six-year-olds from Swansmere School in Surrey will be performing at the Schools Prom at the Royal Albert Hall on November 6.

They will be worth hearing. At the National Festival of Music for Youth at the Royal Festival Hall in July, adjudicator Leonora Davies was delighted with them. She particularly liked how they listened with “with enormous concentration,” and were not afraid of pauses and silence. “Their scores were a delight and they had a particularly strong group identity,” she said.

Behind school music there’s nearly always an enthusiast, someone who loves music making and has the ability to help others enjoy it too. Ray Allen is head of Swansmere School at Walton-on-Thames, which has about 350 three to seven-year-olds. He has been teaching music at the school for nearly 30 years. and in his spare time conducts and composes for the Ambleside Community Orchestra.

He studied with Benjamin Frankel, but ran into difficulties early in his teaching career when running a school orchestra. A local authority head of music didn’t want him to continue because he had no professional training. But his headteacher backed him to the hilt and he has never looked back.

He has taken children to perform at the Festival Hall eight or nine times now, and last year he and a secondary school colleague created a two-hour concert which involved 400 performers from 12 nearby schools playing in musical styles ranging from four-part harmonies to rock ‘n’ roll.

At Swansmere, children learn the music in class as specified in the national curriculum. But Mr Allen supplements this by taking a group of 30-40 children recommended to him by class teachers for one hour a week. It is this group which has composed the music which they will play at the Albert Hall.

“Children have more innate musical than linguistic ability,” he says, “so it’s just a question of guiding them towards expressing themselves musically. ” He begins each session with the group by getting them to listen - “very important and very rare these days when children have so much visual stimulus”. He is certain that the skills of paying attention, concentrating and listening are transferable and that they are as relevant outside the music studio as they are in it.

At the listening session he introduces his group to the music which is to be played at assemblies. “I prepare the children, so they often cope with Stockhausen much better than the teachers,” he says. After that the children begin to work on the huge variety of percussion instruments in the studio equipped by grants and donations over the past two decades. They have a bass xylophone, two bass metallophones, Korean and Temple blocks, Tam Tam and Chinese gongs, as well as other ethnic percussion instruments and electronic samplers.

The compositions emerge over several months. He first gives the children a letter to take home which requests that they produce - either with their parents or on their own - a story which he and the children can then work on musically. He then helps them to shape their ideas, and from this interaction the finished compositions, and the very large scores, emerge. “Setting up a feedback loop is what it is all about. They have got to have immediate feedback, even if it is critical.”

To prepare for the Albert Hall he will have two Sunday rehearsals to reintegrate the children - some of whom have moved to their next school - into the ensemble which was so impressive at the Festival Hall. He is aware as a headteacher how disruptive this kind of intensive activity can be, and the difficulties that being chosen or unchosen creates for the children.

“Keeping everybody fully informed about what’s going on is one way of minimising the strains,” he says. Perhaps the sheer pride in the school’s and the children’s performance helps to smooth any ruffled feathers.

Swansmere is special, but what about less fortunate schools and less confident teachers? Ray Allen believes that the key to making good music in schools is the support and direction of the head. After that he feels that what individual teachers need is enthusiasm and the right materials.

He uses and recommends schemes devised by Brian Dennis (OUP), George Self (Universal) and Geoffrey Russell Smith (EMI). Music, he admits, probably needs more planning than other subjects and he thinks information technology should be used as much as possible. Festivals such as Harvest and Christmas should be turned into real musical opportunities.

For teachers who aren’t musical he suggests sometimes handing over the class to another teacher who is. “The staff who are musical have got to support the staff who aren’t,” he says. And teachers should choose a wide range of music for children to listen to so that “they can make a start on judging good music from bad”.

When children compose he thinks teachers must trust them. “Staff must be prepared to accept emergent sounds, just as they are prepared to accept emergent writing,” he says.

Thirty-three groups of young musicians will be performing at the Schools Prom at the Royal Albert Hall on November 4-6. Ticket shop: 0171 589 8212