Spotify is a hot new streaming music service. That means you use Spotify to listen to its library of 15 million or so tracks anywhere you have an Internet connection. You don't have to purchase a single track, nor do you store any files on your computer; the music streams from the Spotify servers over the Internet.
Except, that is, for those tracks you ripped from CD or downloaded from another service that don't appear in the Spotify database of tunes. Here is where Spotify is different from other streaming music servicesit lets you listen to your own tracks as well as those in the Spotify library.
Understanding the Spotify Local Library
Spotify lets you import audio files you either downloaded to your PC from other websites or ripped from CDs you've purchased. These so-called local tracks are then integrated into your own personal Spotify library.
You can then create playlists that contain both streamed and local tracks; you can even share your local music with your Spotify and Facebook friends. It's a great way to expand the Spotify offerings with those personal favorites you've previously collected.
Note, however, that when Spotify "imports" a file into its library, it doesn't actually upload that file on to the Spotify servers. Instead, it links its library to that file on your computer's hard drive. For this reason, you can play local files only on the computer on which they reside, not on other computers connected to the Spotify service.
Spotify lets you import music files in the universal .mp3 format, as well as Apple's .m4a format. This means that you can easily consolidate your entire iTunes library into Spotify. Unfortunately, Spotify is not compatible with Windows' .wma audio file format, nor can it import files in FLAC and other lossless formats.