Get the latest entertainment news, reviews and star-studded interviews with our Independent Culture email Get the latest entertainment news with our free Culture newsletter Get the latest entertainment news with our free Culture newsletter What defines a “cult film”? Where once the phrase referred to something specific – a movie often with a low-budget, always with a small but devoted audience and bereft of mainstream appeal – now it’s used promiscuously: a modern “cult movie” seems to be any film that people really enjoyed but that doesn’t star Spider-Man. (The moniker was even applied to, say, Everything Everywhere All at Once – which made nearly $150m at the box office and swept the Oscars.) When filmmaker Matt Johnson, however, describes Nirvanna the Band the Show the Movie as a “cult movie”, just know: he really does mean it? The film, out in UK cinemas this week, is a loose followup to a TV series, Nirvanna the Band the Show, itself a niche but adored comedy following two harebrained musicians (Johnson and co-creator Jay McCarrol) and …