At the Sainsbury-sponsored BBC Youth Choir of the Year competition in Buxton Opera House last December, something was missing. Choir after choir stood up and demonstrated the impeccable precision that is the hallmark of this great national tradition. But by the end, the overriding impression was that spontaneity and rhythmic drive were lacking - that there was room for choirs to be a little less precious and a little more in tune with the real world. There are, after all, many ways of using groups of voices to make music, from gospel choirs and barbershop quartets to the Spice Girls. The adult section of the Choir of the Year competition, in fact, usually shows more adventure in its style and choice of repertoire than does the youth section.

Leaders of school choirs, though, have been relatively slow to explore alternative ways of singing together. But there are some schools where music teachers have chosen to play a different tune.

Two teachers in particular exemplify, in different ways, the quest to look beyond the British choral tradition. Their two schools could hardly be more different. North-ampton High School is a prestigious independent day school for girls. Here Bette Gray-Fow, who came to the school less than a year ago as head of music, is leading her girls, with much success, into an exploration of the gospel sound.

More exciting, though, she is encouraging them to improvise individually over “riffs” sung by the rest of the choir. At rehearsal they show a striking level of skill and vocal energy, and an enthusiasm to plunge in and have a go. It is an approach that demands acceptance of some rough edges. Ms Gray-Fow says: “We spend so much of our lives worrying because it’s not spot-on, and hey, it’s all right.”

None the less, Ms Gray-Fow’s background is as a voice trainer and a professional singer, and she takes no chances with vocal production. Almost half the short rehearsal consists of vocal warm-up exercises carried out with skill and sensitivity as well as a sense of fun. And the school’s concerts have an added dimension - the choir’s medley of music from the film Sister Act, which Ms Gray-Fow obtained by special request from the United States, always goes down a storm.

Ifield Community College in Crawley, by contrast, is a comprehensive that struggles in the league tables. Its well-established choir, though, is a jewel in its crown and has been directly responsible for raising the aspirations and self-esteem of hundreds of pupils over the years. The choir gives many concerts, has appeared in prestigious halls in the UK and abroad, and is preparing for a return trip to Barcelona later this year.

The repertoire is eclectic. Gospel songs, Crosby, Stills and Nash, a touch of Oasis, madrigals, music from folk traditions in Africa, New England and other places - all are grist to the mill. The distinguishing feature, though, is the sound. Choral director Patrick Allen is suspicious of the highly trained and cultivated style of vocal production, and believes in what he calls “the natural voice”. The result is exciting, energetic and uninhibited.

At rehearsal, none of the 50 pupils aged from 12 to 16, almost half of them boys, has sheet music. “We have few music readers,” Mr Allen says. “So I’ve had to work without the barrier of the written notes. It’s forced me to understand vocal parts as musical lines - to say, ‘your part goes like this’.”

The rehearsal is astonishing and moving. To see, for example, a sixth-former enthusiastically leading his section by body language, turning so learners can hear what he is singing, is a revelation. Earlier, another boy had explained that he had come to the school with no musical background but was now taking A-level music. “I wouldn’t be doing music if it wasn’t for the choir.”

What is the alchemy that changes a school choir from being an elite activity into something dynamic and popular that will bring new members flocking and audiences to their feet? Here are some pointers: * Change the starting point. Many teachers bring with them the repertoire they learned at college. Try asking the pupils what they want to sing. Ifield choir arose from a single pop concert in 1987 which included a few vocal items, one of which was the 1960s pop song “California Dreaming”. Mr Allen asked himself: “What kind of things would I like to have done at school?” * Have no auditions, but be welcoming and inclusive. The music must fit the choir. Later - as Ifield choir has triumphantly shown - the most non-selective group will gain enough confidence and ability to tackle the most difficult repertoire.

* Try to get away from the printed page. Teach by singing the vocal line. As an aide-memoire, Mr Allen gives out sheets with simplified notation that show pitch but no rhythm or note values. He also uses rehearsal tapes.

* Use riffs - repeated rhythmic phrases upon which, for example, a spiritual or gospel song can be built. Both choirs make much use of this technique. Build it up part by part until the room is filled with it. Pupils love it.

* Constantly search for repertoire. Ms Gray-Fow found a source in the US for the Sister Act music. Mr Allen has contacts all over the world. He also listens all the time to radio and records.

* Be ready to make your own arrangements - reduce popular songs to chord structure and you are most of the way there.

* Do not feel you have to run “senior” and “junior” groups. Ms Gray-Fow says: “I asked them whether they wanted to divide by age group or by interest, and they overwhelmingly chose the latter.” Both the choirs include first-formers and sixth-formers, and this has become a strength. A group of senior girls at Ifield say that as 12-year-olds they had watched and admired a group of leading seniors, “and now we are them”.

* Accept the ability and expertise of the young people. Do not put them in a straitjacket. Pointing to talent competitions and the popularity of karaoke Mr Allen says: “Ordinary people can do amazing things without training.”

* Consider running open singing sessions, perhaps one lunchtime each week, that do not carry the name “choir” and are separate from it. Sing simple, powerful and popular items. This will help raise the profile of singing, and may well bring recruits to the choir. Mr Allen calls these sessions “power singing”.

* Be open-minded. Try to avoid making pupils feel music is not for them, or sending anyone away from school believing they cannot sing.

Patrick Allen’s Singing Matters - a photocopiable resource book for classroom singing at key stage 3 - is published this spring by Heinemann Educational at Pounds 39.95