The Avett Brothers’ ninth album arrives with an open letter by Seth Avett, in which many words are written but very little is said: True Sadness, he explains, is a patchwork quilt, both thematically and stylistically, wherein “the roughest denim and the smoothest velveteen” entwine. Given their 16-year climb to success, their digression into more unusual textures feels like a bid to break out of the tweed and into something a little more mainstream. This is certainly their most varied release yet: beyond the traditional country, bluegrass and folk, the North Carolina act expand their sonic palette. May It Last is their Pink Floyd moment, while Satan Pulls the Strings reveals their wild side with a crisp, metallic sound. They also shift temperament: the yodelling on Divorce Separation Blues deliberately skewers a serious subject matter with a knowingly frivolous melody. But for all the talk of creative epiphany, their music remains the country-tinged comfort blanket it always was.