Is iTunes touching my library files automatically and/or in the background?

Question

I am currently using a service called Cubby (it is like Dropbox) to sync my iTunes library between several computers. I would expect then that syncing only occurs when I add to or delete from the library. But I notice that often the Cubby app will be actively syncing when I haven't made any changes, and it will give notifications that (for example) a song changed which I definitely did not recently add/remove.

Likewise I have lately been seeing weird changes in filename and track number tags. I wonder if this is iTunes trying to organize something automatically and failing?

So does anyone know if iTunes will routinely modify your library files and how/why? What is it doing?

Answer 1

Playing files would alter the iTunes library file, as that tracks play counts and last played dates.
It might also store certain info (like rating) in the meta-data of the files as well.