iTunes Match Is Finally Here: Go Download The New iTunes Software Now To Give It A Try [Silicon Alley Insider]
With iTunes Match, all the music files on your hard drive that you've obtained by copying them from a CD – or some other more nefarious means – will be matched with iTunes' 20 million song library. After matching the files, you can upload them easily to iCloud and play them on any iOS device.
iTunes Match is available for an annual subscription fee. After purchase, iTunes Match scans your music collection to see if the songs are available on iTunes. If so, the songs are automatically uploaded to iCloud. If a song is not automatically matched, iTunes will still upload all of your songs to iCloud, but the process will be much faster since it's likely that the majority of the songs in your collection will have been matched and don't need to be uploaded. Perhaps the best part is that your matched music will play back from iCloud at 256-Kbps AAC DRM-free quality, no matter the quality of the original track.