Another Gameboy genius, NeX is at it again. What he has done is to connect the clock output from LSDj to 74161 and 4024 counters then that is sent through (what I assume is) a slewrate limiter kind of thing to control attack and decay. Then that signal iscontrolling the frequency of a LTC1799 variable oscillator which is contralling the clock frequency of the DMG running Shitwave. (Don’t forget that Shitwave sucks though!)
Notice how there’s an interference pattern with the screen update frequency and the left boy. And that this pattern oscillates at different frequencies as the clock speed is being modulated.