Not too long ago, it seemed like Sony BMG was willing to die on the digital rights management (DRM) hillside rather than climb to the top along with its fellow major international recording labels the EMI Group, Universal Music Group, and Warner Music Group. But today, Sony BMG announced that, after six months of testing various waters, they were making at least some of their catalog available DRM-free.

In a move that would mark the end of a digital music era, Sony BMG Music Entertainment is finalizing plans to sell songs without the copyright protection software that has long restricted the use of music downloaded from the Internet, BusinessWeek.com has learned. Sony BMG, a joint venture of Sony (SNE) and Bertelsmann, will make at least part of its collection available without so-called digital rights management, or DRM, software some time in the first quarter, according to people familiar with the matter.

Given Sony BMG’s history of screwing people over with CD-installed rootkits, this is especially good news.

When Amazon opened their MP3 download store, it was with only EMI and Universal – Warner and Sony BMG were holdouts, hoping to convince their fellow labels to form a downloading service that was a direct competitor to Apple with industry-created DRM attached. But when Warner Music bailed on DRM in late December (conveniently between Christmas and New Years, when very few people were keeping up on the news and could shout “nyaah nyaah nyaah nyaah nyaah” at them), it became only a matter of time until Sony BMG was dragged along into the 21st century.

Back when I heard that Amazon was offering up an MP3 download service, I was convinced that the competition would break Apple’s near-monopoly on music downloads. And we saw the first signs of that very thing when Apple was forced by Amazon’s lower prices for DRM-free music to lower their prices to match. But Apple had something that Amazon didn’t – a lock on the music distribution for two of the major lables. Now that lock has been utterly broken, and it won’t be too long now before the music downloading marketplace becomes a consumer’s paradise with the ability to purchase DRM-free music from the source with the lowest price. Subscription-model companies like Rhapsody will have to either offer more downloads for the same amount of money or will have to transition over to a per-track model – they risk going out of business otherwise. Downloaded albums (for us dinosaurs who still listen to complete albums), already available significantly cheaper on Amazon than the physical CD, will become even cheaper.

Today was a good day for DRM to die.