So there are new things to see here and there, but it's not a brand new game. Much like the main game, it holds new content and events under a tight lock and key. You'll have to grind through dungeons and do a lot of fighting and searching before you're given the next morsel of story, or bit of information, much less something new to look at.
As for sound, while there still isn't background music in this new dungeon, but there is a bit of new sound content. There are sequences where you hear a mysterious voice singing. It's a simple humming tune, followed by some eerie piano and soft singing voices. There are moody low notes, setting the tone like the best ghost hunting TV shows would. It's kind of a shame that most people will probably skip through this, and with good reason. You only hear it when the text box comes up and tells you about the mysterious disembodied singing voice. This means as you advance through text to read the next line, it will end. There's so little sound, and the battle music is so repetitive, that these little original pieces are quite nice, so it really is a shame they end so quickly unless you make an effort to listen to them.