You’d be amazed how much of your Mac’s storage is wasted on the iTunes library. All those apps and media you have purchased and downloaded over the years pile and clog up your Mac’s precious storage.

But with one-terabyte external hard drives retailing for less than $60 on Amazon, there are no excuses not to spring for external storage to move that humongous iTunes library of yours on.

This post takes you step-by-step through the process of consolidating your iTunes library and moving it to an external drive in a way that will preserve your playlists, ratings and other interactions, so you won’t miss a beat.

About iTunes folder

Apps and media you purchase, along with any files imported to iTunes and all your interactions are kept in a special folder on your computer. To locate the iTunes folder on your Mac, choose Go → Home → Music → iTunes in the Finder menu.

The iTunes folder on your Mac
To locate the iTunes folder on Windows, go here:
Windows XP: \Documents and Settings\username\My Documents\My Music\
Windows Vista: \Users\username\My Music\
Windows 7 or 8: \Users\username\Music\
The iTunes folder is home to these items:
iTunes Library.itl—This is the primary database that iTunes relies on heavily to organize your media, reference the files and store your playlists, play counts, ratings and other data. If deleted, it cannot be easily recreated from scratch.
iTunes Library.xml—A version of the “iTunes Library.itl” file in a format that’s readable by third-party apps, allowing them to access your iTunes media. Should you accidentally delete this file, iTunes will recreate it on next launch.
iTunes Library Genius.idb—This file stores data about your music library that the Genius feature uses and is created upon enabling Genius in iTunes.
iTunes Library Extras.itdb—This file holds Gracenote CDDB information.
Album Artwork folder—This folder is where iTunes saves album artwork that was downloaded automatically from the iTunes Store or added manually. It also holds a cache of album artwork that iTunes needs for the Cover Flow feature and regular album displays.
iTunes Media folder—When you drop one or more files onto the iTunes window, iTunes adds media to your library and copies the original files to a sub-folder labeled “iTunes Media,” which by default lives inside the iTunes folder unless a custom location was set.
Here’s a snapshot of my iTunes folder in the Finder.
iTunes folder

What’s inside iTunes Media folder?

You’ll find a handful of sub-folders in the iTunes Media folder:

  • Audiobooks—Your purchased or imported audiobooks are stored here.
  • Automatically Add to iTunes—Throw one or more files in this folder and iTunes will automatically import supported media into your library.
  • Downloads—Temporary stores any unfinished downloads.
  • Mobile Applications—Your iPhone, iPod touch and iPad apps are kept here.
  • Movies—Imported or purchased movies go here.
  • Music—Your imported or purchased songs and albums.
  • Podcasts—Downloaded podcast episodes go here.
  • Tones—iPhone ringtones created in iTunes are stored here.
  • TV Shows—Imported or purchased TV shows are stored here.

Should you elect to have your iTunes Media folder organized, iTunes will place song files into album and artist folders. Individual files will adopt the file name format based on the disc number, track number and the song title.

Keep iTunes media folder organized

If you choose to prevent iTunes from copying files to the iTunes Media folder when adding items to your library, copying the entire iTunes folder to an external drive won’t copy the referenced media files that live outside of the iTunes folder.

That’s where iTunes’ library consolidation feature comes to the rescue.

Why you should consolidate your library

Consolidation ensures everything in your library is stored in one place. You’re recommended to consolidate your library before moving the iTunes folder to external storage. Doing so will copy media files that live in other locations into the iTunes Media folder.