The so-called ‘Sun’ quartets of Joseph Haydn’s Op. 20 are often said to represent an unprecedented flowering of his string quartet writing, establishing a high watermark to which every other subsequent composer of quartets has paid homage. The six quartets are not a monument of compositional rectitude or propriety, however – it is rather their flexibility, variety and unpredictability that make them so compelling. Every bar is full of a sense of musical adventure, a palpable feeling that Haydn is creating bridges between styles and ideas and forging a composite vision of four-part string writing that draws on every historical source that he knew as well as the furthest reaches of his musical imagination. On this second instalment, the last three quartets of the set are performed by the Chiaroscuro Quartet, a highly international ensemble formed in 2005 by the violinists Alina Ibragimova (Russia) and Pablo Hernán Benedí (Spain), the Swedish violist Emilie Hörnlund and cellist Claire Thirion from France. Dubbed ‘a trailblazer for the authentic performance of High Classical chamber music’ in Gramophone, the quartet plays on gut strings, and the previous instalment was singled out as a recommended disc by The Strad, whose reviewer described its contents as ‘period-instrument performances of the utmost subtlety and refinement’.