From Amazon forum/kindle
Most of us have quite a few downloads from ITunes and those we've downloaded from our CDs to ITunes. And we REALLY didn't want to pay again for these. Now the Amazon Cloud bring us a big gift----being able to transfer iTunes music to Kindle Fire completely free:
Notice: Special for Your iTunes store purchased files that are not DRM protected.
Use the Amazon Cloud. you can store your music on the internet, and the amazon cloud player has an mp3 uploader that automatically scans the music in the itunes and media player folders. so long as your music is in mp3 format, you can upload it.
It provides 5 gigs of storage for free, and all amazon purchased music doesn't count towards the 5 gigs.if you have about 3k songs, and it took maybe half a day of your computer uploading it all the the cloud. Once you get your fire, it will be able to play music from the cloud directly, or you can download some music directly to it.
And you will find that not only musics, all your iTunes Libs, PDFs, audio books and what have you (etc), were automatically overhauled to your Amazon Cloud.
So if the the Fire it said playback error if I tried to play a song when you try to sync to iTunes, the playback error occurs because Kindle fire only supports aac and mp3 files. Other music is in WAV, AAC, AC3, AMR, MP2, Flac, OGG, AIFF need additional tool to convert the music files to Kindle Fire supported Mp3, AAC. And iTunes to Kindle Fire Converter for Mac is a perfect app to convert all kinds of iTunes audios and videos to Kindle Fire directly playing audio and video formats. Video including Non DRM M4V, common MP4, MOV, DV etc.
Easy guide on iTunes music, video to Kindle Fire(Lion included):
Step 1: Click "Add File" to add video from your PC Hard Drive to.
Step 2: Set Kindle Fire supported format:
Audio supported within Music: AAC LC/LTP, HE-AACv1 (AAC+), HE-AACv2 (enhanced AAC+), AMR-NB (.3gp), AMR-WB (.3gp), MP3, MIDI, Ogg Vorbis (.ogg), PCM/WAVE (.wav)
Kindle Fire Video: H.263 (.3gp, .mp4), H264 AVC (.3gp, .mp4), MPEG 4 SP/ASP (.3gp), VP8 (.webm)
Kindle Fire Audio:
Kindle Fire Video:
recommend resolution: 720p.
Step 3: Click "Start" button to begin convert iTunes music to Kindle, or convert iTunes Video to Kindle.
