I want my music widget to be shown on the screen in a similar way that RemoteControlClient works. I don't want the users to be needed to have the widget added to the lock screen beforehand. The samsung music app on thier 4.2 devices have this behaviour.
AFAIK, this isn't possible in the public SDK. Samsung's apps may be able to do it on their device because they are developed by Samsung for their own devices and have greater access as preinstalled system apps.
No API that I am aware of does this as of now.