it is now posted: https://www.youtube.com/watch?v=0-F1O-B4v98.

So, before 4EverfreeBrony left in July, he was able to help out with the vocals on this massive collaboration, called Be A Bolt. It is a parody of "I'll make a man out of you" from Mulan. It is going to be premiered on dec 15th at 11pm central time on Celestia Radio's Pubcrawl. And then the video will be released shortly after on Joaftheloaf's channel.

https://www.youtube.com/user/Joaftheloaf