The "idling, not in a boss room, not in a room with monsters" theme for occult floors. If I can suggest this, perhaps adding in these "idle songs" to the song list? They're quite ominous, just like Wild Isle :]. Kinda good for PvP'ing (not so much pking for me :] just like soul wars or something "safe"
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Zaros Stirs is so beautiful. It reminds me of a few Zelda games.
And Norse Code is one of my favourites. I was surprised when Mozzie from White Collar mentioned it while they were cracking the music box. But I just love it! I've even gone as far as to learn it on piano.