Following last week’s announcement that Warner would add its catalog to Amazon’s DRM-Free MP3 store, this was bound to happen sooner rather than later: the last major label to hold out on selling DRM-free MP3s, Sony BMG, is reportedly getting ready to abandon copyright protection software.

The details of Sony BMG’s scheme aren’t finalized just yet, but it’s expected to begin this February 3rd with the upcoming Pepsi/Amazon Superbowl promo, in which 1 billion DRM-free songs will be given away. By joining Warner, EMI and Vivendi Universal in providing DRM-less tunes via Amazon, Sony will likely help wrest some control of the digital download market from Apple as these unrestricted MP3s will work with iTunes and the ubiquitous iPod.