Amazon.com and Warner Music Group on Thursday announced that songs from the studio's entire catalog will now be available without digital protections for customers of the Amazon MP3 store.

The deal further marks the death knell for digital rights management, or DRM, a controversial technology that restricts the usage of music purchased online. New York City-based WMG and Sony BMG were the last two of the Big Four labels to hold out on DRM-free downloads.

In April 2007, EMI announced that it was ditching DRM. In August 2007 Universal Music Group, the largest of the major labels, began offering DRM-free music downloads.

Last week Sony BMG made a commitment to artist-specific DRM-free downloads, and now WMG goes DRM-free catalogwide.

"Give it four more days and we can finally say that 'DRM is so 2007,'" said Michael Goodman, an analyst with Yankee Group. "Music history will document the transformation from DRMed music to DRM-free music as occurring in 2007. I can't imagine anybody doing a DRM deal in 2008."

The commitment to DRM-free music is not  being applied evenly by each of the four major labels. Different online stores have a variety of arrangements with the labels with varying degrees of DRM application, but DRM's death knell has been sounded, Mr. Goodman said.

"The music industry has clearly and completely capitulated on DRM, but is it too little too late?" he asked. "The power shift from the labels to the artists has already begun. The labels are well on their way to becoming simply music distributors, not unlike your local beer distributor."

Starting on Thursday, music from WMG's digital catalog purchased at Amazon's MP3 store will be playable on virtually any music capable device.

Amazon MP3, which was launched in September 2007, offers more than 2.9 million DRM-free songs from 33,000 record labels. Songs are priced from $0.89 to $0.99 and albums between $5.99 and $9.99.