What is royalty-free music?

Royalty free means you just need to pay for the item once per end product thus eliminating backend royalties and instead charging a clear and simple one-time fee. This payment covers the usage of that music track for the life of that project.

What Can I do with the music?

The music licensed from AudioJungle is intended to be integrated into a larger project such as a part of a youtube video or commercial.

Can I use a track as a stand-alone music track? 

You may not use music in stand-alone music tracks.  The tracks are intended to be used as a part of a larger project.  For Example: You can’t add lyrics to an audio track and sell it on iTunes.

Can I add lyrics and sell it elsewhere like on iTunes?

It is against the license terms to use the track as a part of another musical work.  For example you can’t sample parts of the track or add instruments or do a remix of the track for resale.  You are also not allowed to add lyrics or sing a vocal on the track and sell it.  The music cannot be repackaged and sold as another stock item.