If you want to get free Katy Perry songs from YouTube you need to install a Youtube to mp3 download application on your computer. Go online right now and list all of the different YouTube to mp3 downloaders that come from reputable software developers. If you want to know with certainty whether a software company is reputable or not you need to read over the comments posted online by other people who used the software. After you have completed this review it should become clear which of these applications is truly the best out there. Now that you know which of these converters is the best you should install it and begin downloading all of your favorite Katy Perry songs.