i am very positive its all key presses. other than the hijack long knob press. for fun (because it makes coo noises) i like to hit down up down up down up down up down up as many times as possible, as when it catches up it does two disctinct beeps in succession over and over.
its not just this one song that does it, but in all the songs that it does it on it always catches up at the same moment in that song. different times per song.