Google is unveiling its much-anticipated digital music store as it opens a new front in its battle with Apple to provide services over mobile devices. For the first time, Google will sell songs on the Android Market, its online store for apps, movies and books. Songs were priced at free, 69 cents, 99 cents and *1.29. Some examples of artists whose work is available right away include Coldplay, Drake and Pearl Jam. The songs are automatically uploaded for free into a customer's online locker, and then can be streamed over computer and mobile phone browsers, including the Safari browser that comes on Apple Inc. devices.