aniel Fishkin is an artist with the kind of tenacity that is mostly reserved for politicians and mountain climbers. When he was in college, he became fascinated with the daxophone, an experimental instrument played by drawing a bow over a thin piece of wood known as a tongue that’s clamped to a wooden block. The daxophone was invented by the reclusive musician and typographer Hans Reichel, so Fishkin e-mailed Reichel, asking to purchase one of the instruments. His request was ignored. Undeterred, Fishkin began his own course of daxophone tutelage, seeking out a teacher and crafting his own tongues and eventually taking an immersion course in German. Three years ago, he arrived on Reichel’s doorstep and they spent a week together, talking shop and building new instruments. Now, in his quest for still more exotic and interesting sounds, Fishkin has turned to yet another source: circuits. Specifically, the interaction between light and sound, as perceived by a series of cathodes and a battery.