THE atmosphere in the music room of Garrowhill Primary School in the east end of Glasgow is one of deep concentration. Young eyes dart between the teacher at the front of the room and the percussion instruments, behind which each child is stationed. The xylophone player drops a stick and misses a beat; a giggle ripples through the tension before the junior music group seamlessly pick up the song, Eco Rap, which they wrote under the guidance of teacher Pamela Moore.

The children are among 7000 amateur performers - mostly youngsters - from the UK, US and Canada preparing to take part in the Glasgow Music Festival, which starts tomorrow. Garrowhill has entered three groups - a music group and two verse speaking groups - and hopes to replicate its success last year, when pupils won the Gilmour Bar Trophy for their efforts.

The two-week festival, which runs until March 17, is one of the biggest of its kind. Although described as a music festival, the event, which first took place in 1911, encompasses public speaking, poetry recital, dance and even news-reading.

Over the years the emphasis has moved from competition to participation - every entrant is judged by a professional and receives a certificate evaluating their performance. Performances, which total more than 170 hours, will take place at Glasgow Royal Concert Hall, Woodside Halls and Renfield St Stephen's Church, and are open to the public.

Several well-known musicians have cut their performing teeth at the festival. These include William Conway, conductor, soloist and artistic director of the Hebrides Ensemble, who was also principal cellist with the Scottish Chamber Orchestra and co-founded the Chamber Orchestra of Europe; Douglas Boyd, the British oboist; and Gillian Findlay, who played violin in the London Symphony Orchestra.

Even for those who are not interested in a career in performance arts, there are many benefits to be gained from participating. Richard Buchan, headteacher at Garrowhill Primary, believes taking part is a valuable experience for the children. "It really builds their self-esteem and confidence. Children who perhaps aren't as strong in the traditional subjects can shine in music and drama. Expressive arts is very much a level playing field, which is good. Lots of children really rise to the occasion of performing in front of a real audience; it seems to motivate them."

Like many of the organisers, festival chairman Robert MacDonald took part as a child, singing in choirs and playing the cello. He believes the positive experiences people take away from the event help drive the festival forward. "The volunteers feel they really got something out of the experience when they were younger and are keen to put something back," he says. "Everywhere you go, you meet someone who has a connection with the festival. There is a real sense of history. So many of the participants have parents or teachers who took part: it's a real family event. With so many performers, there is a definite buzz to the city over the two weeks."

The importance of music to children's learning is something that is being recognised by government. From August, the Scottish Executive plans to make it a more integral part of the learning process for children entering primary one, as part of the Curriculum for Excellence. While traditional techniques will remain for reading, writing and numbers, more emphasis will be placed on using drama, music and art in lessons.

For those who want to learn how to play an instrument, the opportunities are improving. Jack McConnell, the First Minister, made a commitment to increasing access to music lessons for all pupils in 2003. Critics say this commitment has been watered down, but the introduction in Dumfries and Galloway last year of specialist music tuition by video conferencing has been welcomed. The pilot scheme allows pupils at rural schools to receive brass tuition from a teacher almost 100 miles away.

The executive also set up the Youth Music Initiative (YMI) in 2003 to widen access to tuition. The scheme, administered by the Scottish Arts Council, has been extended to 2008 and has a total budget of £37.5m.

David McDonald, youth music manager at the Scottish Arts Council, says: "The Youth Music Initiative has found that the wider benefits of engaging in music-making activities include increased levels of attainment, confidence, behaviour and concentration. Above all, music can provide a fun, valuable learning experience." Ian Smith, head of music at the Scottish Arts Council, believes the incorporation of music can have benefits in other areas of education, both academic and social. "Learning to play a musical instrument helps with literacy, numeracy, listening skills and hand-eye co-ordination," he says. "Playing in a musical group can be of great benefit socially. Because it is something which children opt to do and which their peers are doing, it is seen as cool. And it gets young people involved with the world, which ultimately makes for better citizens."

Smith says the Youth Music Initiative has been a resounding success in introducing more children to music tuition both in and out of school. "The investment from the YMI has given extra funding for more teachers and instruments, and the original aim to give one year's free instrumental tuition to each child up to primary six has been achieved in all 32 local authorities."

Back in the classroom of Garrowhill Primary, what do the pupils themselves feel they gain from participating in musical and recital groups? For 11-year-old Ruth Geddes, who is performing a solo verse recital as well a group one, a large part of the appeal is social. "You can make friends who are in different classes, who you wouldn't normally speak to." Callum White and Craig MacIntyre, also 11, play for the school football team but enjoy the challenge of poetry recital. "There are lots of different after-school clubs but most are sports clubs. We wanted to take part in this one because it was something a bit different," says Craig. "It's quite scary going up on stage but afterwards it's exciting, and getting to see the school's name in the paper makes me really proud," adds Callum.

Eight-year-old Kyle Thomson says performing in public has boosted his confidence. " I took part last year, too, but I feel more confident - you get used to being in front of an audience. It makes me feel braver about doing other things, too."

Some of the group are natural performers. Rachel Shannon, aged seven, is also entering the solo recital competition. She was invited to audition by music teacher Mrs Moore. "I just love getting up on stage and performing," she says. For others, the incentive is more prosaic: "I auditioned for the group because you get out of class," says eight-year-old Abby Taylor.

Whatever the individual motivations, the collective enthusiasm is tangible. Beethoven said music can change the world. It's a sentiment these youngsters would recognise as they prepare to face their public.