The German poet Goethe said, and is duly quoted in the booklet here, that a string quartet is "a spirited conversation among four reasonable people." That is not what Bach's Art of Fugue is, but string quartets seem impelled to keep performing the work, and audiences buy the move; the rarefied air of the string quartet seems to fit with Bach's contrapuntal mysteries somehow. This release by the Cuarteto Casals made classical best-seller charts in the late spring of 2023. It is one of the better string quartet attempts, both hewing to and departing from the work's Baroque character. First violinist Abel Tomás Realp mostly cultivates a glassy sound with little vibrato, as if his line were being played on an organ, but the other players allow themselves to be more expressive. The general approach is deliberate, and the members speak at length in the interview-style booklet about the necessity for deep contemplation in approaching the work. It is almost as if the group is seeking to clarify its contrapuntal intricacies. The music broadens out in the four canons, which are placed at the end right before the final fugue. That is given a little conclusion rather than being left hanging, as in Bach's unfinished manuscript, and it leads into the chorale Vor deinen Thron tret' ich, BWV 668, which Bach himself might have intended. The sound from Spain's Cardona monastery fits with the goals of the performance, which is to add a new layer of mystery to this perennially troublesome work.