Free YouTube to MP3 Converter allows you to extract and download all videos from YouTube. You just need to copy and to paste the URL of the video. The audio files are saved as MP3 (high quality, optimal, standard or economy) or as WAV in "My Documents" and the name of the original video is kept.
Warning: Before using this software, make sure that you have the right to download the video and the audio track. Do not forget the copyright!