Apple’s artist-driven music network “Ping” was basically dead on arrival, but Twitter thinks it has what it takes to make a successful social music service. The company on Thursday unveiled Twitter Music, the worst-kept secret in social networking. The service helps users discover music based on what their friends are listening to, along with recommendations from popular artists. “It uses Twitter activity, including Tweets and engagement, to detect and surface the most popular tracks and emerging artists,” Twitter said in a blog post. “It also brings artists’ music-related Twitter activity front and center: go to their profiles to see which music artists they follow and listen to songs by those artists. And, of course, you can tweet songs right from the app.” Twitter Music will be available on the web and on Apple’s iPhone at launch, but Twitter plans to expand it to other platforms moving forward.