Mastered For iTunes for High Fidelity Music

"Apple's trying to differentiate iTunes from its competitors with a new "Mastered for iTunes" section that's filled with high-fidelity, ear-pleasing music."

If you aren't happy with the run of the mill iTunes music, head to the Mastered for iTunes section to get some higher quality tracks. These files minimize the lost data that happens when music is compressed, so you get more of the dynamic range of the original 24-bit source file. You can get much more detailed information than I am able to provide by heading over to the Mastered for iTunes site located here.