One always needs a dose of originality after a large helping of nostalgia and that was certainly provided by Showstopper, a new comedy show during which a cast improvises a musical using suggestions from the studio audience. Curtain up on the first offering, and Dylan Emery was asking the ensemble for an opening number for a musical called The God Sister set in mafia gangland. Not surprisingly, the plot was nonsensical at times, or as Emery put it, "contextually unlikely", but on the whole the performers - including Pippa Evans, Ruth Bratt, Lucy Trodd, Sean McCann and Oliver Senton - produced one of the most entertaining half hour's radio I've heard in a long time.