Ahhhh my bf's friend showed us a few weeks ago this site that allows you to do that....lemme see if I can find it.
https://www.youtube.com/watch?v=zg3vs7oh32s"]YouTube- Record / Capture Audio Any Music Video - No Programs Needed
get a boombox and a cassette tape and put it up to the speakers. then open up sound recorder that comes with windows and play the tape up to your computer's microphone. use a program to convert from wav to mp3 and there you go.
Sites like that are advertized all over youtube in the video comments. They're safe, as far as I know.
If you don't wanna use any of those just download an audio recording program and record the video.. It's not gonna be great quality but it will work. EDIT: Actually sometimes it's good quality.
http://www.applian.com/sound-recorder/ This is by far the best Iv found on the net. No need to mess around with copy and pasting it just records any sound playing and you can choose what format and what quality to record it at :cheers2: