Amazon.com has announced that it will be adding music from Sony BMG to its Amazon MP3 DRM-free music store later this month, which will make it the only service to offer DRM-free tracks from all four major labels. “We are excited to offer Amazon MP3 customers DRM-free MP3s from SONY BMG, which represents many of the most popular musicians from the past and present,” said Bill Carr, Amazon.com Vice President for Digital Music.  “Our Amazon MP3 customers will be able to choose from a full selection of DRM-free music downloads from all four major labels and over 33,000 independents that they can play on virtually any music-capable device.”   “We are excited to be working with Amazon as they continue to build new markets for digital music,” commented Thomas Hesse, President of Global Digital Business & U.S. Sales for Sony BMG. “We are constantly exploring new ways of making our music available to consumers in the physical space, over the internet and through mobile phones, and this initiative is the newest element of our ongoing campaign to bring our music to fans wherever they happen to be.” In addition to offering DRM-free music from all four labels, Amazon MP3 also features tracks from more than 33,000 independent labels, and now offers over 3.1 million songs from more than 270,000 artists.