Unlocked recordings

Advertiser supported music; Music that is free to consumers and sponsored by advertisers is an "unlocked recording."

http://blog.criticalworld.net/2007/05/01/peter-gabriel-and-ad-supported-music/138/
http://ad-supported-music.blogspot.com
http://www.wired.com/entertainment/music/commentary/listeningpost/2007/07/listeningpost_0709
http://opinion.latimes.com/bitplayer/2007/09/online-media-ro.html

Advertising is paid, one-way communication through a medium in which the sponsor is identified and the message is controlled by the sponsor. Variations include publicity, public relations, product placement, sponsorship, underwriting, and sales promotion. Every major medium is used to deliver these messages, including: television, radio, movies, magazines, newspapers, video games, the Internet (see Internet advertising), and billboards.