About iTunes and ID3 tags

Q: Due to my PC being fairly old and iTunes’ rather heavy reliance on resources, I tend to use iTunes primarily for managing my library/syncing my iPod, and a simpler application for playback when I’m working at the PC. However, I keep running into a problem with changes that I make to a song in iTunes (like genre or year changes) not taking effect when I play the file using a different application or when I load songs onto a different brand MP3 player.

I always assumed that when you use the ‘Get Info’ option to modify the information about a song, iTunes made the changes not only to its database, but also to the tag within the specific MP3 file itself; but this doesn’t always seem to be the case.

About iTunes and ID3 tags

Are there certain fields within an audio file’s tag that iTunes will not change, or do I have something set incorrectly?

– Rachel

A: Your assumption that iTunes should update the ID3 tags within the media files themselves is absolutely correct. Unfortunately, however, there are some factors that can prevent this from working as it should.

This problem occurs most commonly with MP3 files, and is often the result of either corrupted ID3 tags, or simply the fact that the files are using an older version of the ID3 tag standard, known as ID3v1 tags (ie, version 1).

ID3v1 tags stored a very limited amount of data in a fixed-length format, and made no provisions for extended information such as album artwork or any of the more advanced metadata in iTunes (ie, album artist, disc number, grouping, composer, etc).

Compatibility with ID3v1 tags was further complicated as many programs adopted their own (often-incompatible) standards for encoding this additional metadata into the file using the ID3v1.1 format, which allowed for some basic extensions to the ID3 data area.

While iTunes is normally supposed to update whatever tags are already in the file, we have observed problems working with ID3v1.1 tags over the years, most frequently due to this additional non-standard data that may have been added by other applications which may have touched the files in the past.

You can check which version of ID3 tag is contained in the file and being used by iTunes simply by viewing a track’s properties.

Select an MP3 track, and choose File, Get Info from the iTunes menu, and check the “Summary” tab:

About iTunes and ID3 tags

Note that an MP3 file can have both ID3v1 and ID3v2 tags contained within it. iTunes will normally use the latest version of the tags it finds to populate the information in its database, although it will try to update both versions. However, iTunes does not attempt to rewrite the entire tag header—it merely updates those fields that it finds within the tag.

The simplest way to fix this issue is to convert the ID3 tags within your MP3 files to the newer ID3v2 standard. There are several sub-versions of this, but you should generally use ID3v2.4 (the latest) provided your other applications support it, which almost all modern MP3 playback and management applications should.