If you need a quick and easy way to grab an MP3 version of the music on YouTube (and many other sites including Facebook), try ClipGrab. It’s free and works on both Mac and Windows. It’s great for getting files to load into Transcribe!. The website is: https://clipgrab.org/
You can download the video in MPEG4 or audio only in either MP3 or Windows media. Other formats are supported.