A midwinter night’s dream at the Barbican. Those who like their pop music performed by chaps with jeans, preferably gazing at their shoes, and are attached to certain ideas of authenticity would have run screaming for the exit. The Irrepressibles were pop as icy spectacle, as dizzying melodrama, while Gabby Young & Other Animals were raiding the musical dressing-up box and emerging with bits of French chanson, German cabaret and slinky tangos, and having a ball doing it.