Bookmarks vs. Download Settings for Yahoo! Music Unlimited Subscription Music
If you subscribe to Yahoo! Music Unlimited, you may choose how your subscription music is provided to you. Subscription music refers to the tracks you get as part of your monthly subscription, those that are added to My Music when you click the Add button.
Download: This is the default setting. This means that subscription music you add is sent to your computer as a full downloaded file, which takes up space on your hard drive. The benefits of this choice are that you can play the music if you are offline (i.e., if you use a laptop and are not connected to the web); and if you transfer music to portable devices regularly, the files are already on your computer and don't have to be downloaded individually to transfer.
Bookmark: This setting changes the Preference such that songs you add as part of your subscription are added merely as bookmarks in the Yahoo! Music Jukebox and not as full downloaded files. The benefit of this option is that you don't take up space storing music files on your hard drive. The drawback is that you cannot play these songs when offline since they are not downloaded to your hard drive.
To change the preference: In the Yahoo! Music Jukebox, select Edit > Preferences ... and select Y! Unlimited in the left frame. In the box "When I Add a Selection to My Music," click the radio button for the option you wish. Going forward, that will be the way subscription music is stored. You may always return to this Preference and change the option.