Britain's Got Talent, last semi-final, ITV, review Britain's Got Talent worked its production magic right from the start of tonight's live semi-final, and a performance from three girls known as the CEO Dancers. "It was much more than just watching three dancers," raved judge David Walliams, which was incontrovertibly true - the three CEO girls had been joined on stage by no fewer than six scantily-clad men. Perhaps bribing the producers to triple your act is the way forward for all contestants in the future. But the next contestant, singer Aliki, followed straight on by ramping up another tried-and-tested BGT tactic: she literally sobbed during the VT of her own sob story. "I was not, genuinely, expecting that from you tonight," commented Simon Cowell after her performance, and it was hard to know if he was talking about Aliki's song or her emotional manipulation. After a week of patchy live shows, ITV had at least started this last semi-final with a creditable run of acts. No blokes dressed as vicars dancing with broomsticks dressed as nuns - campy gay dance troupe Glambassadors offered a much slicker routine, in their hot pants and their rhinestones. And ventriloquist Steve Hewlett raised the roof when he swapped his usual dummy, Arthur Lager, for a viciously accurate foam version of Cowell himself. Then things went downhill. "You couldn't have made it worse if you'd tried," said Cowell pithily, to out-of-tune 80s-throwback Maarty Broekman. To Broekman's credit, he did turn up with his entire act - which was more than could be said for Duelling Pianos, down from two blokes at the audition to one bloke tonight, and thus not really living up to the whole "duelling" aspect. Poor "duelling" Rob got undeniably short shrift from the judges. Seeking meaning in their comments has become one of the best bits of BGT: every night, it's been pretty clear who we're meant to vote for. Tonight, things were so non-committal that I was wondering if we were going to be left to our own devices - until the very last two acts. Pretty-boy Irish singer Jordan O'Keefe, with his rendition of Whitney Houston's (or is it Dolly Parton's?) I Will Always Love You had Cowell virtually picking up the phone and voting for us. And tonight's last turn, the shadow-art group Attraction, had Amanda Holden and Alesha Dixon in tears - a sure sign that their act (which was a heart-wrenching musical life story, sort of like a John Lewis ad in silhouette) is meant to go through to the final next Saturday. But why were they performing against a screen that appeared to have a line of staples down it? One thing missing from tonight, sadly, was any real controversy (except when Simon took a drive-by pop at Katherine Jenkins). All week, BGT has been dogged - or should that be hyped-up? - by Bruce Forsyth's claim that it's wrong for kids to be allowed to perform on the show. Tonight's resolutely post-pubescent line-up for the very last semi-final removed that argument - but, with it, removed perhaps the most interesting thing that BGT 2013 has had going for it. It hasn't been a vintage year for Britain's Got Talent, and tonight's wasn't a vintage semi-final. When all the froth has died down, will next week's final produce a Paul Potts or a Susan Boyle? I would, as Simon Cowell might say, be genuinely surprised to see that.