A concert-goer takes a spin with a hand-held electronic Concert Companion at a New York Philharmonic concert. “It was amazing, in fact: to my untrained eye and ear, the text invariably arrived at exactly the right moment. And there was something exciting, or at least satisfying, about reading that the concertmaster traditionally plays the solo and glancing up to see said concertmaster sawing away.” And yet, there were some problems…