The viola is an inherently quixotic instrument. Its construction is a compromise between an acoustic ideal and human limits: For its sound to bloom as effortlessly as that of a violin or cello, its neck would need to be impossibly long. For most of the instrument’s history, composers have conspired to keep it out of the limelight, assigning it a supporting role. And chamber music conventions dictate that on the rare occasion that a viola does get the melody, it’s facing the wrong way.