To sing a piece of music on stage for the first time is one thing; to sign your performance for deaf members of the audience at the same time is quite another. Yet that is the skill being taught to more than 80 children in the primary section of the Dundee Schools Music Theatre.
The workshop is for their first production, a showcase of songs from well-known musicals collated under the title When Children Rule the World, which will be performed at Dundee's Whitehall Theatre this Sunday.
After that taxing session, the children move swiftly into an energetic song-and-dance routine. Over the clatter of feet and lusty singing their tutor is urging them to use their faces as well as their bodies to communicate the words.
Down a maze of corridors, in another room, four 10-to 11-year-old girls are gathered around a baby grand piano with the company's music director, Paul Clancy. They are singing a tricky piece from Cats and making an enviable job of it.
Trying harder, doing more and doing it better lies at the heart of what this thriving company is all about, but only recently have primary school pupils been included.
Dundee Schools Music Theatre has informally existed since 1998 with the aim of teaching pupils from the city's 10 secondary schools the skills necessary to produce musical theatre. A year after its first production, Guys 'n' Dolls, in October 1999, a formal partnership was established between Dundee City Council's education department and the Whitehall Theatre, where its performances usually take place. Since then, the company has performed at Dundee Rep, the Edinburgh Festival Fringe and the Millennium Dome.
At the moment, it is gearing up to do the newly-released schools' version of Les Miserables in August in Dundee.
The company's work has been increasingly recognised and last September it received pound;57,000 from the Scottish Arts Council's National Lottery Fund to develop its work. That now involves skills-based workshops, covering stage fighting, juggling, costume design, make-up, lighting and so on. Importantly, the funding has also allowed it to employ professional tutors, and that has opened up staff development opportunities for the voluntary teachers involved in the project.
The theatre's education programme does not stop in the rehearsal rooms. The pupils are taken along to professional productions, where they are expected to evaluate the performances as well as enjoy them.
Ever since it was formed, there has been an increasing demand for younger pupils to get involved. So last September, the theatre opened its doors to almost 300 hopefuls from Dundee's 41 primary schools, of whom just over 100 P6s and P7s were accepted into the company's new section.
Lina Waghorn, the education services manager with Dundee City Council and the driving force behind getting Dundee Schools Music Theatre started, is enthusiastic about what it offers children beyond the chance of being on stage. "We look at how the body works, voice projection, how to speak to people, how to engage with people using body language and eye contact, and how to listen and value others," she says. "It's almost the ground rules for life."
They learn about health aspects of performance and living, too.
"If you are going to take part in performance, you have to be physically fit," she says. "In the weeks leading up to a performance we talk about diet, about skin, about how we are going to make sure we are applying make-up to a good canvas. All of that is about making the most of themselves. It is about performing in all aspects of life, not just on stage.
"All the children that come through Dundee Schools Music Theatre grow in confidence," she adds. "They have a better belief in themselves, they are able to express themselves in a way that is confident and mature and they see the value of being a team player."
Outside, it is now a miserable, rainy evening. The "team" in the main hall has gone home; the water bottles and sweatshirts have disappeared. The satisfied look in Ms Waghorn's eyes reminds me of what she said when we first met: "The children who come along are the future of the theatre."
'When Children Rule the World', the Whitehall Theatre, Dundee, May 11, 7pm. For tickets, call 01382 433718