You can get AAC files on iTunes a few different ways:
1. In Finder, select your AAC files, and either open them or drag them onto your iTunes logo in your dock to add them to your iTunes library;
2. In your iTunes library, select the MP3 files you would like to convert into AAC format, then choose Advanced from the menu bar and select "Create AAC Version";
3. Songs purchased from the iTunes Store are in AAC format, and they are added to your iTunes library automatically;
4. To import songs in AAC format from a CD, choose iTunes from the menu bar and select "Preferences". Under "General" select "Import Settings", and choose pick "AAC Encoder" from the drop-down list beside "Import Using".
Yes, the iPod will play .mp4 and .mp3. .mp4 files are iTunes songs as you originally downloaded them, and .mp3 files are either converted files that you converted in iTunes or files that you did not get through iTunes. The iPod supports a variety of audio formats: AAC, Protected AAC (from iTunes Store), HE-AAC, MP3, Audible, Apple Lossless, AIFF (as found on CDs), and WAV.
Music files downloaded from the iTunes store come in the format "Purchased AAC", and video files downloaded from the iTunes store come in the MP4 format
iTunes files are standard MP3s or AAC format and so any equipment compatible with these formats will work.
In iTunes Right Click on an MP3 file listed in the Library and select Convert to AAC from the menu that appears.
MPEG-4 audio files can be imported to iTunes 9. They will usually have the extension .m4a or .mp4. The AAC files that you can purchase from the iTunes store are MPEG-4 audio files.
Yes you can. You need to get an SD card and put the music files on there. If you have itunes, you can click on each of the music files and select "create AAC version" and then move the AAC files to your SD card.
AAC files are audio files much like MP3 files. Like MP3, AAC files use audio compression to achieve a smaller file size. AAC stands for Advanced Audio Coding, and it is somewhat more effecient and higher quality than MP3 (depending on the bitrate). When you download a songs from iTunes, you're getting an AAC files. For more information, look up Advanced Audio Coding on Wikipedia.
The default audio formats that can be imported into iTunes are AAC, AIFF, Apple Lossless, MP3, or WAV.
Both Amazon and iTunes supply music at 256 kbps but Amazon supplies MP3 files whereas iTunes supplies AAC (the audio part of MP4) files which are usually slightly smaller file sizes.
You can get the songs from anywhere, but they have to be AAC files, such as .m4a files. You can use iTunes to convert .mp3 and .wma files into .m4a so they will work. A word of warning, though: if you buy songs from the iTunes store only iTunes Plus songs (without DRM) will work on the DSi.
To downgrade an AAC (MP4) to an MP3 file open iTunes Preferences and select the Import Settings in the General section. Change the Import Using: option to MP3 and set the Settings to the desired quality. In the iTunes library right click on the AAC file and select Create MP3 version from the menu.
MP3, AIFF, WAV, MPEG-4, AAC and Apple Lossless (.m4a) including QuickTime's supported files.