I have an album that I want to add into my itunes library but it only adds 5 of 12 mp3 files. I cant work out why it wont add the rest?

It should add them all. Have you tried adding them one by one or in chunks of say 6.

Yes I have tried adding them one by one but the songs will not go into the library.

Have you actually tried looking for them via the song name rather than album? it could also be a corrupt mp3 somehow.

And they're definitely mp3? mp3 isn't a catch all term for digital music files.

They are all mp3 files, same bitrate and play fine in windows media player. I have tried selecting just the individual files but just will not go into the itunes library.

This is the reason why I hate iTunes.

It's something to do with id3 data (metadata in mp3 files that has info like title, track # etc).

Download this software called TagScanner
http://www.xdlab.ru/en/download.htm

It's obviously a Russian program but it's fine, doesn't have trojans or spyware and it's a great free program for what it does.

It does various things... I use it a lot to standardise the naming style of all my music tracks by renaming tracks from the metadata info.

But in this instance:

Open program
Click on the Tag Editor tab
Click on the folder icon on the right of Path at the bottom. Find the folder your problematic album is in, and you're taken back to the program.
Select all the tracks in the big window.
Click on Auto in the top right window. I'd select the top option, ID3v1.
Now with the tracks still selected, click on Save at the bottom. This is basically just resaving what info is in your files, but as a certain formatting style.

Try reimporting into iTunes when you've done that. If it doesn't work, go down through the options in Auto and try again.