Can't Delete iTunes Content I have a MacBook Pro running the latest version of Yosemite and the most up to date version of iTunes.

When opening iTunes up it shows that I have 6 songs, I've tried to delete these songs multiple times by right clicking, pressing 'show in finder' and then moving them to the trash, but they still won't disappear from iTunes no matter what I do. I've even removed the caches folder but no luck even after restarting.
Removing them from your hard drive has no bearing on whether they show up in iTunes. You have to actually remove them from iTunes, too. (Right-click > Delete or Edit menu > Delete while the song is highlighted) The (nearly) only time iTunes knows whether a file in the iTunes library actually exists on the hard drive is when you try to play it.

Also, if you use the above method, it will offer to remove the song from your hard drive at the same time it is removing it from iTunes.