Zun knew, so he did XD Remember, he was born into the 8 bit era, so obviously he had contact with the BEST we ever made Ost sound. He then made music and knew perfectly well someone will do this in proper 8 bit later (also adding actual LORE to touhou and expanding it, wich he is still incapable off)
Though hard to judge now, since it's been a while, It's very possible. A lot of the time, there will be references to other arrangements of a given song
My guesses: It’s a crayon. She is a schoolteacher, after all. It’s a scroll. She does have the ability to manipulate history, after all. It’s a stalk of bamboo. She is in the Bamboo Forest of the Lost, after all.