These six sonatas, likely dashed off in the early 1720s between Bach’s weekly cantata duties at the Thomaskirche, were intended to be played at home or in Leipzig’s bustling coffee houses. Violinist Lucy Russell captures something of their intimate charisma. Her playing is stripped-back and silvery – whispered and introverted in the fourth sonata, searching in the third – but slightly earnest in some slow movements and laboured in some faster passages. Harpsichordist John Butt reigns in his most rambunctious side (listen to his recent recording of Bach’s Well-Tempered Clavier for a taste of that), but revels in the invention of the contrapuntal lines and fully embraces the keyboard’s emancipation from accompanying role to sparring partner. His woozy rubato might drive some listeners crazy, but I’m all for it; this is playing rooted in bulletproof scholarship, but the scrunchiest harmonies and most roguish dance rhythms always win out.