Update: I’ve reposted this article because with the release of iTunes 11, the Gapless Album tag is no longer available in the program. However, many people don’t understand this, and think that the removal of this tag means that iTunes no longer plays music without gaps. This is incorrect. Read on and understand what this tag was for.
Following a comment from a Twitter friend, asking how to find which of a number of albums require gapless playback, I pointed him to an old article on this website. (I won’t link to it, as it was written in 2006, and addressed the problem of gapless playback on the iPod.) I realized that many people don’t understand what that Gapless Album tag is, so here’s a brief explanation.
If you select a number of tracks in iTunes, then choose Get Info, and click on the Options tab, you see this:
And if you choose a single track, you see this:
That tag at the bottom of the first screenshot, Gapless Album, or at the bottom of the second, Part of a Gapless Album (thanks for being consistent, Apple), has one, and only one usage. This tag only matters if you have Crossfade Song turned on in iTunes (Preferences > Playback), and it only affects playback from iTunes. All gapless albums are automatically detected and played as such on iPods and other iOS devices. You may even see iTunes “Determining Gapless Playback Information” when you add new files to your iTunes library; this is simply to find whether the music ends at the end of the file or not. (Not actually at the end, in fact; there’s a brief bit of silence no matter what, but it’s a set length, so if the silence is that length, iTunes knows to ignore it.)
So, unless you use Crossfade Songs, you never need to worry about this tag.