Is it legal to download audio from a YouTube video if it was posted by VEVO the artist's record company or someone else who owns the copyright?

Although im not sure, it's Most likely Illegal. :/

Still though, Everyone does it! :D

If it is public resources and you only download it with a streaming audio capture, it is legal.

Note: People who use a streaming audio capture to record online music or audio is not allowed to publish it.