YouTube features hundreds of thousands of videos and music clips: the user sometimes wants to get the music of a clip to listen to it on his MP3 player, or just add it to his multimedia collection. This is also a place for authors to show their musical work: even if the music can't be bought, they sometimes forget to give a link to the MP3 file.
This software is purposed for downloading YouTube videos and then converting them to MP3: this way, you can easily copy it on any MP3 player to enjoy the music even if you are away from your computer.
You would possibly like to get both the MP3 and video: YouTube Song Downloader can do it for you. When you click on a video, you can decide if you want to download the song, the video or both. If you prefer the .ogg format, then simply go in the settings and change the audio format accordingly. If you want to get a better quality or if you are running out of space, you can change MP3 quality settings: you can choose between 128kbps and 320 kbps. The video format can also be changed: you can choose between .avi, . mp4 and .flv. If you want to change the folder where music and videos are downloaded, you can enter the Settings section and click on the right button "Change", in accordance with whether you want to change your music output folder or your videos output folder.
To conclude, this software is a great YouTube download manager. The free version, however, has ads and requires you to register after your 30 days trial.
It should also be mentioned that I got error messages during my tests when trying to download music or a video.