"This is an indubitably splendid tune, it reminds me of the nibble of 1887!" - @hollowknightenjoyer0 (from youtube comments)
"As many have guessed, this is indeed the musical interlude that plays when your lanterns are extinguished in the first entry in the iconic fear-inducing stageplay series, Five Sequential Evenings at Sir Frederick Fitzgerald Fazbearington's Abode." - @discomacabre1 (from youtube comments)
Be careful, someone's watching you when lights go out :)
