stripping video soundtracks

[#1]

Is there a way of removing the soundtrack from a video on YouTube that is legal, and leaves you only with the soundtrack, in a form that could be stored on, and played as, an audio CD. The original video is not a professional product, but the music is. It is an very old recording (made in the mid-1950's I think) that is no longer available as a CD, and I have only been able to find it on this YouTube video.
Thanks for your help

[#2]

JDownloader does the job for me. It downloads the various video resolutions as well as the audio (usually as mp3) which can be burnt to CD using something like ImgBurn.
Not all videos will download this way and then I use 4K Video Downloader. At this point I have a sledgehammer to crack a nut but there are various tutorials regarding extracting audio from video or you could try something like Any Audio Converter - I haven't any experience of this myself.

[#3]

I just use good old VLC.
http://www.videolan.org/vlc/index.en_GB.html

[#4]

I've got VLC Media Player - is that the one DaveyH meant? I have just tried using it to convert from an mp4 video to an Audio-mp3. It didn't actually say it had failed but it didn't show any signs of progressing either. I tried again, but converting to Audio-CD - same result. Am I doing this wrong?
I have also tried downloading JDownloader, but got a "this page cannot be displayed" message. As above, am I doing this wrong?
Thanks for your help

[#5]

Did you get my P.M.  ?  simples... 

[#6]

I use this :
http://www.flvto.com/youtube-downloader/
Just watch out for all the "optional extras" that try to install when you install it.

[#7]

I have a solution. Pazera Free Audio Extractor. At first when I tried to download it, I got the "this page cannot be displayed" message again, but I tried downloading it from that site that has lots of free software downloads on it (I'm deliberately not naming it because of what I am about to write, and it may not be their fault) - the download had a lot of "extras" that I didn't want, and spotting them before they got in was a bit of a problem. However, I think I stopped the baddies, and after installing Pazera, I have run it, and produced a good mp3 version of the soundtrack of the video.
My thanks to all for your help, and Merry Christmas