Half-past four on a Monday, and 13 students are sitting in a room with a variety of instruments, mostly percussion, listening to each other very carefully. They are in three groups, each with a newly developed piece. The works, barely a minute long, all have distinct musical elements - of structure, of rhythm and of dynamics. Then they're told to change them. They have two minutes, and no talking. (She's strict, this teacher.)
Actually, they're all teachers. They come from primary schools in the London borough of Hackney, and most of them had no musical skills until about nine months ago, although they are all required to teach the subject.
For non-specialist teachers, music can be the most daunting subject in the curriculum, which is why the Hackney Music Service and the London Symphony Orchestra developed this two-year course. For those taking it, now at the half-way point, it has already transformed their ability to teach music, and given them a confidence in performing, creating and talking about music few of them believed they could have.
For the LSO this is one segment of a broader community programme, LSO Discovery, which celebrated its third birthday last month. It is based in the Hawksmoor church of St Luke's in Old Street, owned and newly restored by the orchestra, and a 10-minute walk from its main base at the Barbican Centre.
In its short existence, the orchestra has grown to work with every sector of the community, from six-month-old children with their mothers onwards.
Each year it runs 250 gamelan sessions, 90 music technology workshops, 100 community events, 40 teacher training sessions and 30 events for the elderly and disabled.
At the heart of LSO Discovery, says its head, Andrew Burke, is the work it does in schools. It gets to about 2,000 pupils in Islington and Hackney each term, through working in the schools or having groups visit St Luke's itself, with its generous work spaces, well-equipped technology suite, two gamelans and, most important, musicians from the orchestra.
"The idea," says Andrew, "is to root ourselves in a community which might not have thought music had anything to do with them."
"Of all the kids we work with," says Rachel Leach, LSO's animateur, "I would say 95 per cent of them have never been to a concert. I meet kids who have never heard of Mozart."
The LSO, like most arts organisations, has been involved in outreach work for many years, but the base at St Luke's means that, for the first time, lasting links can be formed with the community, rather than the in-and-out approach which is a feature of so much of this kind of work. They are even starting their own instrumental teaching programme, in response to a demand they have largely created themselves.
In their own borough of Islington, their work is based around St Luke's. In neighbouring Hackney, says Andrew Burke, they want to reach every school in three years. They also cemented a relationship with the borough during the 1990s, with the establishment of Make Music!, their two-year continuing professional development course for non-specialist primary teachers.
Make Music! took the best part of two years to develop, says James Thomas, head of instrumental services in Hackney. It is divided into a foundation year, designed to develop the teachers' own skills - including learning to play an instrument - and a second year in which they transfer their skills to the classroom. "The key element," says James, "is to make teachers feel more confident. They get exposure to different kinds of music, and the teachers and their pupils get to see live musicians at work. We want them to be able to link what they hear in LSO concerts with what they are doing in the classroom, to develop an understanding of music from the inside, about different styles, and to see how the fundamentals of harmony, rhythm and melody all come together."
Those who wish to can go on to get diplomas in music facilitation of specialist music training, accredited by Trinity College of Music.
Feedback has been enthusiastic. "We've learnt how to bring music into the classroom in a structured way," says Kirsten Simmons, a teacher at Burbage School.
"Confidence is the big thing it's given us," says Karlie Walsh of Grasmere School. "Before, I couldn't stray from the schemes of work because I didn't really understand them. And if you're not sure what you're doing the children can feel it, and then they don't enjoy it so much. Now I can teach children the recorder and take music assemblies, things I wouldn't even have thought about doing before."
They also love working with members of the orchestra. "A whole day working with them and then a performance is a great way of understanding more,"
Rachel Leach, one of the teachers on the course, wondered how working with the LSO players would affect them. "It was amazing. We had teachers who had no musical experience before last September discussing with these players how an ostinato was going to go, discussing times and what to beat.
Suddenly all the things they had been learning became real."
* John Galloway explores St Luke's work with schools, alongside other music and ICT coverage, at www.tes.co.ukonline