You can call it “drone” music, but the word “drone” has, of course, come to be synonymous with hovering agents of surveillance. So, Michael Rooke, the Finnish sound designer and coder, just calls it “One Note,” or at least that’s his name for a recently posted track. There is, arguably, more than one note to “One Note,” since that note dangles like a platonic ideal amid all manner of light, nuanced variations. It sounds like a bowed glass harmonica more than anything, this one intoned sound on repeat, the lulling pace of its sine wave see saw occasionally usurped by secondary, deeper tones. As Walt Whitman said in a different context, this one note contains multitudes.