When Tony Castro arrived for his interview at the BRIT Performing Arts Technology School the corridors were festooned with children picking on guitars, humming songs, composing tunes and jamming together. “I thought it was a set-up,” he says. “They were just trying to make the place look good.” But after two years as head of music at the school, Tony knows that impromptu jamming in the hallways is as much a part of this school as the double glazing.

Creativity is a much sought after quality in schools, but here at the BRIT they seem to have it in spades. Take the school concert - not for the BRIT the painful scratching through the classical repertoire, with pupils and parents holding on to rictus grins in a gallant effort to squeeze an iota of enjoyment out of the occasion. Here, in the specially built auditorium, an enthusiastic audience shake their booty to a dazzling display of musical genres from hard rock to gospel - performed, composed, arranged and produced by the Year 12 students. Some of them will be joining the line-up of star graduates from the BRIT, including chart-topping Katie Melua and accomplished jazz singer Amy Winehouse.

However, despite its unique range of courses - in drama, musical theatre, production and dance, as well as music - the BRIT is more than a south London version of the Fame Academy - a comparison principal Nick Williams is keen to avoid. “Our aim has always been to offer encouragement to talent and to offer a rigorous education,” he says.

The school’s creativity is anchored in a solid academic track record.

Nearly nine in every ten pupils leave with five A-Cs at GCSE - the third highest in Croydon - and its value-added score puts it in the top 20 comprehensives in the country. How’s it done? Everyone at the BRIT is anxious to point out that the reasons for success lie within the students themselves. “A lot of it is about their ability to take responsibility for their work and do it themselves,” says Liz Penney, deputy head of music.

BRIT students don’t spend all their time tinkling keyboards or fingering frets. The B Tech national diploma covers theory and history of music, the music industry (a business component of the diploma) and sequencing (which takes in ICT), as well as recording and performance.

“If you want to be a serious musician, then you need to stretch your intellectual grey cells,” says Tony. “We emphasise that the paperwork is just as important as the performing. OK, you can write rubbish lyrics if you want to - but if you want to write quality lyrics that transform the music, then paying attention to English literature and language is part of what you have to do.”

The BRIT’s intake starts at Year 10, with 14 to 16 students who take eight GCSEs in “ordinary” subjects, as well as the B Tech First - equivalent to two GCSEs. Each day consists of a combination of classroom teaching and time in the rehearsal rooms or studios - four-and-a-half hours each week of music, as well as individual instrumental lessons.

Students taking the B Tech national diploma (equivalent to two A-levels) can also opt to take extra A-levels, and many of them do. Students can specialise in various forms of music, including classical and jazz, but the firm emphasis on pop betrays the schools origins as a creation of the record industry.

For the B Tech national diploma, post-GCSE students have to compile a portfolio of work, based on performance and paper. This is broken up into 18 units, each of which might contain one, two or three assignments. A typical example might be that by the end of the first term, students will have had to compose and perform an original 12-bar blues. Students are then placed into performance work groups. The idea is that they can’t just go off and write a song - they must learn how to work with others, and write down the steps they took to come up with the finished product.

Self-evaluation is as essential as the finished product, explains Tony.

“Interactive skills, communication skills - these are skills that the professional musician needs in the industry.” Teachers give individual feedback as well as an in-class critique, and work is graded according to B Tech criteria as pass, merit or distinction.

Performing is at the heart of the BRIT culture. Each of the five annual terms involves a performance that is assessed and counts towards final marks. But, in one sense, they are performing all the time - not just for concerts, but also in the school foyer, community centres and even a local music venue.

There are 300 applications for 50 places in the BRIT music department every year. Students are chosen by audition, although school reports are also taken into account. However, says Liz: “At this stage, it is potential we are after, not accomplishment.”

“What I say at open days,” adds Tony, “is this: if a student doesn’t wake up every morning desperate to do music, then the BRIT School is probably not for them.”

But the school also remains committed to its catchment area - it lies in a hard-pressed area of South London. For the BRIT is about providing opportunities, particularly to those who may have a love of dance or music but whose families or previous schools do not have the wherewithal to help them explore it.

As chair of governors Jack Deacon, founder member of the record industry trust, which set up the school, puts it: “What we are proud of is that most young people who come here have been square pegs in round holes. After they have been here a while they have a new confidence and belief in themselves.”