John Buckman, the founder of the radical, sharing-friendly, artist-paying label Magnatune, sez,
The Magnatune music service has been transitioning from a "buy album downloads" model to a "DRM-free, all-you-can-eat, pay-what-you-want" model. I believe that Magnatune is the only DRM-free all-you-can eat pay music service.
Today, Magnatune removed all commitment requirements for membership, so that literally you can join for $10 and get access to all Magnatune albums and downloads.
This marks the end of a 3 month experiment, in tandem with Yochai Benkler's research group, to see what effect different prices, pay-what-you-want strategies, and commitments might have on a post-scarcity online music business model.
Membership without obligations
(Thanks, John!)