I'll try to be more specific :)
1.- I was just wondering if you could be more specific as to when you're trying to notify a user?
Answer : when someone press the play button on my app it will run and the user can listen the music , then , if he press the "menú" button or the "red call button" the music still listening but i wanna create a message on the notification bar (i think that's the name) , so if he drop down that bar the user can click the message and be back on the app.
2.- As far as updating a label displaying the name of the song, I was wondering what components you're using (I assume the Player component) and how you are using them (what kind of web resources do you use for your radio app)?