OK, so you're wondering if there's a way to sell music on iTunes for free. Well, technically speaking there isn't. However, you can put yourself in a scenario which would lead to free distribution.
Right now, there is a company called ADED.US Music Distribution. They have a package called The Ultimate Package. If you purchase the Ultimate Package (for $100 USD), you will be assigned 12 distribution credits. This means that you can distribute up to 12 separate singles, albums, or EPs for one fee. The perk of this is that your music automatically gets distributed to the 1,000+ stores that they distribute music to. So, you can sell your music on iTunes or get your music on Spotify, Google Play Music, Rdio, Amazon, and much more!
Now, that is a clear discount compared to the other music distribution companies that will charge you $50 to distribute one project.
If you are interested in doing business with ADED.US then you can simply sign up on their website, e-mail them (email@example.com) or call them at 702-793-7602
Aside from that, ADED.US has an extensive network where they can promote your music to over 10,000 people on over 30 platforms: