What is "Add to My Music"?
When you see this icon, it indicates you can add this music to the My Music collection instantly, and listen to it, share it with friends, and transfer it to portable devices. In order to add music, you must be a subscriber to the Yahoo! Music Unlimited service. If you are a subscriber, the music is instantly yours to enjoy for the life of your subscription.
If you're not a subscriber, clicking this button will start the subscription sign-up process, which you'll need to complete in order to add the music.
Adding the songs does one of two things, based on how you chose your preferences: either it places a bookmark to the music in My Music or it downloads the full song file.
If you indicated you preferred Yahoo! Music Unlimited songs to be bookmarked in My Music, you'll only be able to hear the song while you're online. If you indicated you prefer music to be automatically downloaded, you can listen to the song whether you're on or offline. We encourage you to leave your Preferences set to download songs so you can enjoy them when offline.
If you are a subscriber to Yahoo! Music Unlimited, the song will be added to My Music immediately to enjoy. The only thing you cannot do with songs added as part of your subscription is burn them to CD.