How iTunes Plus Differs from the Standard AAC Format

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The term iTunes Plus refers to an encoding standard on the iTunes Store. Apple migrated the songs and high-quality music videos from the original AAC encoding to the newer iTunes Plus format. The two main differences between these standards are:

  • Downloaded files aren't encrypted with Digital Rights Management protection.
  • The bitrate is twice the resolution of the original iTunes standard.

Compatible With More Devices

Before Apple introduced iTunes Plus, iTunes customers were restricted on how they could use their purchased digital music. With the iTunes Plus format, you can burn your purchases to CD or DVD and transfer songs to any device that supports the AAC format. This change also means that you aren't restricted to using Apple devices such as the iPhone, iPad and iPod Touch.

However, the newer standard isn't backward compatible: Older-generation Apple devices cannot support the higher bitrate of the upgraded format.

Higher Quality Music

Not only does the iTunes Plus standard give you the freedom to listen to your songs and music videos on a wider amount of hardware devices, but it also gives better quality audio too. Before the introduction of iTunes Plus, standard songs downloaded from the iTunes Store were encoded with a bitrate of 128 Kbps. Now you can purchase songs that have twice the audio resolution—256 Kbps. The audio format used is still AAC, only the encoding level has changed.

Songs in the iTunes Plus format use the .M4a file extension.

If you have songs in the original format, you can upgrade these by subscribing to iTunes Match—providing they are still in Apple's music library.