How to Download mp3 Music From YouTube video YouTube is a bountiful resource for videos, especially for music videos. If you would like to download them to extract the music files, you'll need an MP3 converter or YouTube downloader. You can save the music file to a USB drive or to your computer. You can also online YouTube to mp3 convertor website to save the music video as a mp3 format. Step 1 Log into YouTube, and find the video whose audio you would like to isolate. Copy the video's URL, and in a new browser, visit a website like YouTube to mp3 Paste the video's URL into the Paste link here field, make sure the field just below indicates.mp3, these sites all work just about the same exact way, and all allow you to capture YouTube videos, then press Start Step 2 Click on the option to download video from a website. Step 3 Click the download button. After a few moments, a link should appear. Click on that link to download your YouTube video.