While the anticipation of Boyle's appearance certainly adds another dimension to the production, that should take nothing away from the rest of the show, which is funny, entertaining, tear-jerking and reveals parts of her life that have, until now, remained a mystery.
Elaine C Smith not only makes the role of Susan Boyle her own but is also a co-author of the show. In fact, it is hard to believe anyone else could play the part of Boyle so well, not least due to the physical similarities.
The story is told from Boyle’s perspective, looking back over her life so far at periods that are both sad and painful to watch, but always riveting.
While Act One deals with life before Britain’s Got Talent, Act Two takes us through the auditions and the aftermath. In excess of 30 musical numbers litter the score and each and every one is instantly recognisable (from "At Seventeen" to "Stuck in the Middle With You" and "Paper Roses"). Although many are not immediately associated with Susan Boyle, they are woven seamlessly into the storyline.
The show rightly received an instant standing ovation last night before the star herself had even appeared. When the curtain fell at the finale, the anticipation built, and sure enough when it rose again Boyle herself was standing there.
Further standing ovations followed as she sang two numbers on her own - "Who I Was Born to Be" and, of course, the title number.
But this is a show that easily stands on its own two feet. Director Ed Curtis takes us on a journey through Boyle’s life and never allows the attention to waiver for a second. The scene where Susan’s father (played by James Patterson) dies is one of the most emotional I have seen on stage, while those backstage at the auditions for BGT are nothing short of inspirational.
Producer Michael Harrison (Chess, Jolson & Co, Witches of Eastwick) is known for his record-breaking pantomimes around Britain each year, but this time he has brought us a real life fairy story.
This production is a standalone show that should still play to audiences long after Elaine C Smith and Susan Boyle have left. In fact it deserves to become recognised as the Scottish equivalent to Blood Brothers, so strong are the production values.
There is no doubting I Dreamed A Dream is one of the musical events of the year.