All iTunes Plus tracks feature DRM-free music with high quality 256 kbps AAC encoding for audio quality which the company claims is "virtually indistinguishable from the original recordings."
In addition, the iTunes Plus catalog is now the largest DRM-free catalog in the world, and includes artists from Sub Pop, Nettwerk, Beggars Group, IODA, The Orchard and many others, along with EMI's digital catalog.
"iTunes Plus has been incredibly popular with our customers and now we're making it available at an even more affordable price," said Eddy Cue, Apple's vice president of iTunes. "We're adding over two million tracks from key independent labels in addition to EMI's digital catalog and look forward to even more labels and artists making their music available on iTunes Plus."
EMI began offering their catalog on iTunes Plus earlier this year, and their selection has grown to include singles and albums from the Rolling Stones, Pink Floyd, Norah Jones, Frank Sinatra and the solo catalogs of all four Beatles.
With the expansion of iTunes Plus, customers can now download tracks from a variety of labels without limitations on the type of music player or number of computers that purchased songs can be played on. iTunes Plus songs purchased from the iTunes Store will play on all iPods, iPhone, Windows or Mac computers, widescreen TVs with Apple TV, as well as many other digital music players.
Apple, however, did not comment on how owners of DRM-wrapped tracks purchased from its download service in the past can upgrade to the iTunes Plus versions. Before dropping the price of iTunes Plus tracks from $1.29 to $0.99, the Cupertino-based company charged a $0.30 per-track upgrade fee.
Apple's iTunes Store maintains its position as the world's largest digital media catalog with over six million songs, 550 television shows and over 500 movies and has sold over three billion songs, 100 million TV shows and over two million movies.
Reports that Apple would expand its iTunes Plus service while simultaneously dropping the price of the higher-quality songs were first published by ArsTechnica earlier this week.