Q:My iPod classic and iTunes are all up to date. However the iPod says that there are 15 songs less than what is in the library. Do you know why that would be? When I check the songs, it seems that all the songs are there when I randomly check the music that I update. Is this a common problem? Any information would be appreciated. Thanks.
A: There are a few possible reasons for this discrepancy. One possibility is that you may in fact have items such as digital booklets in your Music library that are not actual songs, in which case these would be shown in the total song count at the bottom of the iTunes window but would not be transferred onto your iPod as it has no way of dealing with digital booklets. Many albums from the iTunes Store come with these types of extras, which are basically PDF files or interactive QuickTime files and can only be viewed through iTunes itself. Digital booklets are identified in your iTunes library by a small book icon beside the track name. You can also add the “Kind” column to your track listing by selecting View Options from the View menu and then sort on that column to group them all together.
It is also possible that these 15 missing files are not compatible with your iPod for one reason or another. Even modern iPods can sometimes still have issues with obscure bit-rates or non-standard track information. While not likely an issue with any music bought from the iTunes Store or imported from your own CD collection, this is not uncommon at all in tracks that have been acquired from less legitimate sources. iTunes should normally warn you if it cannot sync files that are incompatible with your iPod, but you may have disabled these warnings in the past by checking a “Do Not Display Again” checkbox. You can reset these warnings by right-clicking on the iPod in the iTunes Devices list and choosing Reset Warnings from the context menu.
In some cases iTunes will also not copy tracks from your library if they are duplicates of an existing track—that is to say if the track name, artist and album are the same. You can filter your iTunes library for duplicate tracks by choosing Display Duplicates from the iTunes File menu.