I swear there used to be a thread that had a list of themed items/items you could use to communicate with for Mysterious Melody. Is that still around? Anywhere easily accessible?

I too remember that thread, but I looked for it earlier and couldn't find it :(

I remember that thread too. But I think it's because the thread was probably in the Luminaire event forum from last year, and since the event forums start brand new each year, that's why it's not here anymore. Maybe (hopefully) the OP from last year has the info saved and can remake it.