Apple’s new “Mastered for iTunes” has been causing quite a buzz recently – and causing lots of confusion.
I’m going to try and explain it all as clearly as I can.
There are four ways that the term “Mastered for iTunes” can be interpreted.
1. Mastered for iTunes is a set of utilities and guidelines
The easiest to understand and least controversial definition of “Mastered for iTunes” is described on this page on Apple’s site, here:
Basically it’s a set of guidelines for people to follow, to ensure you get the best quality versions of you music files available in the iTunes Music Store. Apple also include free utilities that allow you to preview how your files will sound once they’re encoded.
The guidelines are great – they encourage you to submit the highest quality files, and suggest how avoid falling into common traps that affect the quality – for example avoiding clipping and not over-cooking the music’s level because of the so-called “Loudness Wars“.
At the moment, the final files are still 44.1 KHz, 256 Kbps AAC files – so, they’re perceptually encoded files, using lossy compression – basically like high-class mp3s.
Whether you’ll hear a real difference from submitting a 24/96 version of your music is debatable – my quick tests suggest the answer is “not much” – but Apple also hint that in future they will use the high-quality masters to offer better downloadable versions in future, which can only be a good thing.
So far, so good.