Nokia's Music service has been a secret weapon for Lumia owners -- they get ad-free radio streaming on their phones at no extra cost. The company is driving that advantage home today by rebranding the service as Mix Radio (reflecting the service's main feature) and launching an updated music app to match. The new Mix Radio client centers on Play Me, a personalized stream defined by a few favorite artists. There are also Pandora-style thumbs-up and thumbs-down votes to refine the selection, and it's now easy to share mixes through email, Facebook, text messages and Twitter. As before, avid listeners can spend $4 per month to get unlimited downloads, improved quality and web listening. Current Lumia users just need to update their existing Music app to take advantage of Nokia's smarter audio experience.