No, YouTube doesn't accept straight mp3 uploads, only video files. What you might have seen is that they recommend that the audio portion of your video file be encoded with the mp3 codec. So you'll have to convert your mp3 into a video file format that YouTube does recognize, .flv for instance.
There's various ways to accomplish this. Here's one that's fairly easy and works quite well:
- You'll need to have the packages 'ffmpeg' and 'gstreamer0.10-plugins-bad' installed.
- Then just run this command to convert from mp3 to flv:
sudo apt-get install ffmpeg gstreamer0.10-plugins-bad
Just replace the path and input and output file names to yours. The '131072' is the bitrate of the resulting file (128Kbps in this case) and can be changed as you wish.
ffmpeg -y -i /path_to_your/song.mp3 -f flv -ab 131072 -ac 1 /path_to_your/video.flv
Hope this helps,