Nik Ashton, PYT artistic director said: "The Silver Sword is based on a true story, following the fortunes of four young people as they travel from wartorn Warsaw to freedom in Switzerland. Richard Taylor has turned the book into a very moving and lyrical piece of musical theatre, and PYT is thrilled to have been given the chance to perform it for the first time with such a large cast of young people."

Lynn Hill, PYT director, added: "We are delighted that The Silver Sword has been such a box office success. It is a testament to Richard and the cast that an unknown piece has proved so popular.

"Word went around the town very quickly that this was a production that had to be seen!"

Composer, lyricist and musical director Richard Taylor says he is extremely pleased with its reception.

"This isn't a published piece yet, so to all intents and purposes this was a premiere. It's been a wonderful opportunity for me to see how it works onstage in this form.

"So much has altered as we've gone along – it's been evolving.

"Every night as the youngsters have understood it a bit more, they've changed their performances and it has been different every time. That really made me look forward to every performance.

"Hats off to them all – they've done fantastically well with a very challenging, multi-layered piece.

"Some of them have gone from musical comedies (Honk! and Alice in Wonderland) to this very different, musically much more difficult production, and they have embraced the challenge.

"That's the brilliant thing about PYT – they do everything extremely well – the production values are so high."

And one very special person gave the performance her seal of approval – Ian Serraillier's daughter Helen, to whom the original book of The Silver Sword was dedicated. She came to see the show on Wednesday night – what would have been her late father's 94th birthday.

"He would have enjoyed this very much," she said. "I'm sure he was here, looking down. It was absolutely wonderful."

In a card she sent to the cast she wrote: "I could hardly see for crying! My Dad would have loved it..."

l See Tom Muckley's review of The Silver Sword, page 31