One of the big criticisms of music services is quality, especially for those who want to listen on quality Hi-Fi equipment at home. Apple is keen to make sure you're getting the best music you can with the Apple Digital Masters programme.
Replacing what was previously known as Mastered for iTunes, Apple Digital Masters aims to remaster the original artist recordings so that listeners get a better experience from their music.
Apple says that its Digital Masters are "almost indistinguishable" from those original masters, providing a range of mastering tools for producers, artists and labels to help them put the best quality they can into Apple's ecosystem.
Apple Digital Masters have slowly been rolling out, replacing tracks in Apple's digital catalogue with new 24-bit AAC files. These new files should have a higher fidelity, with less noise that might have been introduced through a lower quality encoding process, so they sound better when they get to your ears.
There's a lot of information on how the process works right here (pdf), so if you're an audiophile or music enthusiast, you might want to take a closer look at what's going on.
Apple says there's no additional cost for Apple Digital Masters, it's just part of the process of improving the quality of the music that Apple offers from Apple Music streaming and iTunes downloads.
"The audio quality is incredible! The piano is the hardest instrument to get right and this sounds amazing," said Lang Lang - and you'll find that Piano Book is an Apple Digital Master, so a great way to experience the quality yourself.
You'll also find the Apple Digital Masters logo appearing on Apple devices in various places. We've spotted it in iTunes against some albums on the Mac and in the Music app on the Catalina beta, for example, so it should be easier to identify higher quality music - and there's quite a lot of it out there.
If you want to listen to some Apple Digital Masters yourself, here's a selection you can try out right now: