The audience was rapt, the pupils were straining at the leash, the masters were poised and posturing. The marvellous theatre created by the eager pursuit of excellence raised its curtains to the public in Waterford this week. There is a bustle of excitement and a keen air of anticipation each day in the corridors of the Waterford Institute of Technology's Department of Music. It comes from the juxtaposition of famous musical tutors and the cream of aspiring young musicians.

The 1997 International Masterclass Festival, presented by Waterford Tourism, allows a rare public glimpse of the alchemy by which superb teachers and practitioners of an art form can guide already accomplished students a little further along the road to perfection.

The gifted students - almost 50 of them - range from nine years of age to 29 and come from 15 countries, including Ireland. "They come here to get that patina of sophistication - that extra something. It's what they used to get in the Middle Ages when there were guilds," remarks Maria Kelemen, one of the principal organisers.

In a feast for the ear and the eye, the two-week festival of classical music features five recitals, two concerts and four masterclasses open to the public.

Two exceptionally talented 25year-old violinists, Catherine Leonard from Cork and Natsumi Tamai from Japan, starred at the opening recital in Waterford's City Hall on Monday evening.

The next day Catherine is back in the role of student, facing her famous tutor, Herman Krebbers, in the first violin masterclass. Krebbers, who made his own first appearance as a nine-year-old prodigy well over half a century ago, leads her through the Second Movement of Mendelssohn's Concerto: "For me, one of the most perfect violin concertos", he tells the public audience of the class.

The professor nods in approval as Catherine holds a long, lingering high note with a single bow stroke. He remarks as an aside, that some players would make two bow strokes for that high note: "I don't like that".

But he urges Catherine to strive to hold the note even longer, pointing out that the orchestra would normally be a fraction of a tempo behind her. This is the sort of "fine-tuning" offered in the masterclasses.

In another class, strings tutor, Ronald Masin, listens intently as nine-year-old Roisin Walters, from Dublin, plays a piece from Handel (she has been studying the violin for six years).

He interrupts her gently from time to time: "Are you going to make vibrato on some of the notes or all of the notes?" and "I found eight quavers, but you play at least 10".

Maria Kelemen explains the meticulous selection process by which the talented young proteges are chosen for the privilege of attending the masterclasses. More than 10,000 leaflets about the masterclasses and the application procedures are circulated to musical conservatories around the world. "All of the students here have been listened to by tape and audition. I had nearly three times the number who are here. One is better than the other one - it was very difficult to choose," she says.

The students' teachers are also interviewed. Although the young people come from as far away as Korea and Japan, most of them are already studying in Europe. Some get scholarships, from the festival sponsorship or elsewhere, and WIT provides accommodation and meals.

These youngsters are not "hothouse" prodigies, artificially forced into precociousness, Maria Kelemen insists: "They're not pushed; they love it. The performing part of it just makes them more vibrant."

A viola player herself, she teaches children as young as two-and-a-half years of age and says that with the right approach their natural talent can blossom even then. "We don't realise how much a two-and-a-half-year-old can do - they're nearer to nature than we are."

She admits, however, that single-minded dedication to music is a hard vocation, with little material recompense. "There are 25year-old kids here still living on their foundations (grants) or their parents. It's not an easy life - it's rather ruthless. It's a cut-throat business because there is so much good teaching going on."

Asked how long it takes to train somebody to become an accomplished violinist, Ronald Masin, Maria's husband, says: "Twelve years, minimum, if they have a lot of talent. If not, it takes more."

On Saturday the festival will feature a new composition, The Waterford Suite, by Dublin composer Rhona Clarke. On Monday the best of the young talent chosen from the festival will take part in a gala concert in the National Concert Hall in Dublin.

This is the second year of the Masterclass Festival in Waterford, and Monica Leech of Waterford Tourism says that it provides access for everyone to good music. "It's a very young festival, with a low profile so far, but it's obviously something we want to build from year to year."

Details of events and bookings are available, tel: 051 873501, extn 489.