Q: My iPod does not show all the songs in a particular genre when I look for songs by genre. For example, I have one genre with 12 songs in iTunes. Two of the songs have the album specified, one has the artist specified, and the other nine have neither specified. All of the songs are on the iPod. However, when I look in that Genre on the iPod, the first screen lists “All” and “Mary Jones” (i.e. the artist). If I choose All, the next screen does not show all 12 songs. It only shows the two songs that have the album listed. If I choose Mary Jones, I (correctly) get the one song that has her listed as Artist. The other nine songs don’t show up at all (under Genre). However, if I choose Songs from the Music menu, all 12 songs are on the iPod and the genre is specified for all 12 in iTunes. Any ideas?

– Matthew

A: iTunes, the iPod and even Apple’s iOS devices have generally shown odd and inconsistent behaviour when key metadata (tags) is not filled in for all of your tracks. Basically, Apple expects that each of your music tracks has a minimum of a title, album and artist filled in, since these fields are used to group tracks on the various menus on the iPod, iPhone and iPad. Similarly, fields like track and disc number are relevant for ensuring your tracks are sorted correctly when browsing by album.

Even when browsing by Genre, iPod and iOS devices sub-group by Artist and/or Album; as you’ve described above, after selecting a Genre, you’re shown a list of Artists, and after selecting an Artist (or “All Albums”) you’re shown a list of Albums. While some devices and/or menu sections will show entries for “Unknown Artist” and “Unknown Album” for those tracks that are missing tag information, this has varied widely depending on the section you’re looking at, the firmware/iOS version in use, and the particular device you’re using. Again, Apple seems to consider tracks with no album/artist tag to be an edge case, since of course tracks purchased from the iTunes Store or other online music services or imported from your own CDs will almost always contain the proper track information.

The bottom line is that you’re going to need to go into iTunes and fill in Artist and Album information for these tracks. If you don’t know the name of the artist or album for a particular track, you can fill in something like “Unknown” yourself and this will at least ensure that these tracks are grouped together by artist/album in those places where the iPod needs to see this information.

See our Guide to Album Tagging, Art and Playlists in iTunes for some additional tips and ideas on how to best tag your music collection.