How to Convert Songs to a Different Encoder Format in iTunes
In iTunes, converting a song from one encoder format to another is useful if you want to use one format for one purpose (such as burning the song to a CD) and a second format for another task (such as playing the song on your iPod). Changing formats is also useful for converting uncompressed songs or podcasts that were created in GarageBand (or a similar audio-editing application) and exported or copied to iTunes.
Choose iTunes→Preferences→General (Mac) or Edit→Preferences→General (Windows), and then click the Import Settings button.
The Import Settings dialog box appears, allowing you to change the encoding format and its settings.
From the Import Using pop-up menu, select the new encoding format you want the song to be in after conversion.
The Setting pop-up menu changes based on the format you choose.
In the Setting pop-up menu, select Custom.
The Custom Settings dialog box appears.
Select the settings you want to use for that encoder.
For example, if you’re converting songs in the AIFF format to the MP3 format, choose MP3 Encoder from the Import Using pop-up menu and then select the settings that you want in the MP3 Encoder dialog that appears.
Click OK in each dialog box to close it.
iTunes accepts the settings for your chosen format.
In the iTunes window, select the song(s) that you want to convert and then choose Advanced→Create encoder Version.
The encoding format that you choose (MP3, AAC, AIFF, Lossless, or WAV) appears in place of encoder on the menu.
The automatic copy-and-convert operation can be useful for converting an entire folder of albums or songs to another format. Press Option (Mac) or Alt (Windows) and choose Advanced→Convert to encoder, and then choose a folder from the Open dialog box. The contents of the folder are copied and converted automatically. If you have a folder of AIFF tunes or albums, you can copy and convert them to AAC or MP3 in one step.