It is a Friday night at the Savoy Theatre in London’s West End and Nicole Scherzinger – barefoot, wearing nothing but a simple black slip dress and minimal make-up, the tips of her ironed, raven hair tickling her waist – is performing to a sell-out house. She is not here as a Pussycat Doll, or a solo artist, or in any capacity as a talent show judge, but as Norma Desmond: the ageing, eccentric, washed-up silent film actress looking for a way back into the spotlight, and the protagonist of director Jamie Lloyd’s utterly electric new version of Andrew Lloyd Webber’s 1993 musical, Sunset Boulevard. “It’s not a comeback,” she drawls, plumes of dry ice dissipating behind her, “it’s a return.”