Apple is facing stiff competition from the streaming might of Spotify, but new rumours hint that iTunes could bite back with a move to HD audio.
In practice, this means sparkling audiophile-worthy streams when on broadband at home, where you might listen through a hi-fi, but slim file streams over mobile broadband. Perfect for saving on that monthly iPhone data cap.
The unnamed source in The Guardian says users wouldn't have to change a thing to see their iCloud music collection upgraded, though it remains to be seen whether Apple will slap additional costs on the rumoured service.
So what is HD audio? Let's break it down.
Recording studios make music in an HD format, which is mixed down to CD quality at 16-bit/44.1KHz. Don't worry about what those numbers mean, just consider it a bare minimum for HD audio.
Digital music from stores like iTunes will usually be in the MP3 or AAC format. They're pretty good for compressing HD audio to iPod-friendly sizes, but in doing so, some quality is sacrificed from the original recording.
Apple's solution is apparently to store HD files online at 24-bit/96KHz in the futuristic HD-AAC format. It can stream from a server at smaller file sizes with tip-top sound quality, and will work with any device that plays the older AAC format, which includes every post-iTunes Apple device.
It looks like Apple has struck upon the holy grail of audio formats, because HD-AAC contains better quality than our ears can even hear -- and then allows for uninterrupted mobile listening to boot.