Keiko Higuchi must be one of the foremost proponents of the human voice as an instrument and Vertical Language is, among other things, a stunning showcase for the power and flexibility of her inimitable vocals. Higuchi’s work lives in the liminal spaces between the jazz, modern classical and avant-garde worlds, and as every track on this sometimes very bare and stark album demonstrates, the result is as difficult or as simple as you perceive it to be.  Take the opening track, “Scenery One” for example. Eleven minutes long, it is in one sense minimalist, consisting of just the sparsest of piano chords and notes, reverberating in darkness, and Higuchi’s wordless vocal acrobatics. But there’s nothing minimalist about that voice, and it goes on for eleven minutes.