Sony BMG has decided to sell a few of its music without digital rights management via Amazon.com.

According to the reports, three of the four major music companies already sell tunes without DRM.

Sony will turn out to be the last of the major four labels to blow away the copyright protection on at least several of the music it sells.

The sources also reported that Sony would encourage DRM-free music during the Super Bowl by the coming month (February) and will sell it through Amazon.

However, it is not clear whether the DRM-free sales will be bounded to the promotion or limited to certain artists, or whether the DRM-free sales would finally relate to Sony BMG’s complete catalog.

Recording companies have had to mess up for ways to support profits in an industry, which is changing quickly.

According to the music industry news site Billboard.com, overall album sales during 2006 felled around 15%, whereas rap album sales sank a whopping 30.

The same report stated that that a 45% increase in digital track sales helped to cover up the entire loss.

The news that Sony is apparently hashing out plans for DRM-free sales generated plenty of buzz because Sony was heavily criticized in the past for a copyright-protecting rootkit that critics classified as spyware.

Afterward, security experts told that hackers set up a method to make use of the rootkit to access PCs and conceal even more malware on consumers’ computers.

It won’t be the first time, if Sony plans to publicize a small segment of its collection for DRM-free sales. In 2006, the company released a Jessica Simpson song without DRM.