WTF where's the music box??

[Yak-50]

Playing the PC(Steam) version of SE4 and have completed all the primary and secondary objectives except for the music box. Difficulty is set to authentic. I have searched every floor, room, crate and bookshelf in the library for this item and it's nowhere to be found. I saw it once the first time I entered the library on my way to searching for Dr Galvani. But at the time I didn't realise it was a music box. It was on a table on the middle floor at one end of the library.

After completing the other objectives, I had to consult a video walkthrough on Youtube to work out what the music box looked like. It was then I realised I had come across it earlier. Anyway, I returned to the library to look for it at the table but it wasn't there. As other people mentioned the location is random but within the library, I searched as mentioned above but found nothing.

WTF is going on? Is this a bug or is the item somewhere else outside the library? At this point, is there a way of skipping this chapter and just moving to chapter 3? I'm really not keen to replay the entire chapter 2 again.

[Nibelungen Finest]

There are some small reading rooms in the ground floor in the library, north side, not in the hall. I found music box in such rooms once, searched there yet?
Also, when you near it the mission indicator will show how far away the box is, maybe that will help too.

[Rydall]

yep it changes every time from the end of the top floor to the middlle of the top floor to a side room in the library on the bottom floor.. its the dynamics of the game

[Yak-50]

Thank you for answering and sorry for my slow acknowledgement. I was so frustrated with being stuck that I ignored the game after posting! I'm playing in authentic mode so there isn't any mission indicator for me. I'll try looking in the small reading rooms as suggested.

[GreyNaide]

Be aware that the music box changes location with every play-through of the map. However, it will always be found in the library. Be extremely thorough by searching every shelf & table in every room, on every floor & you will find it.
Good luck.

[Gordo]

Insane amount of searching. Finally found it in a small reading room directly opposite (well slightly left) the main stairs coming into the main part of the library. Room has a red carpet and 3 white couches. Such a pain in the ass though.