Facebook is rolling out a new post format on the latest version of its iPhone app called Music Stories. The new format lets you share songs and albums from popular streaming music services, starting with Apple Music and Spotify, while friends can enjoy 30-second previews of what you share. The Music Stories format also looks rich within the app. Tapping play turns the artwork in a record-like spinning animation, and a button to listen to the whole track or album on the streaming service is presented on the right.  expand full story