How much does concept matter? Hackneyed as it may be, it’s a question that comes up while listening to the latest album from prolific Dutch artist Machinefabriek AKA Rutger Zuydervelt. With Voices, as the title suggests, is an album of eight tracks composed around the human voice. Heard blind, it’s a fascinating document filled with fascinating sounds that evoke a host of different moods. Reading into it and things get even more complicated or interesting, depending on your view. Machinefabriek crafted a 35-minute piece of music that was sent to the eight vocalists involved, each of whom responded in their…