Hi! I've solved to keep my streaming music playing, even if the app is in background or the lock screen is visible. Please notice, that you have to get your hands dirty and change some lines in xcode.
may somebody is interested, here's my workflow:
1. create an app with an >>iOS Video Object<< and select your music (in my case i've selected streaming content of an internet radio station)
2. export the app to xcode
3. after opening the project in xcode, add this frameworks:
"AVFoundation.framework" and "AudioToolbox.framework"
4. open your app-Info.plist from the Ressources folder and add a line called:
"UIBackgroundModes", add an item to it called "audio" (both will be renamed by xcode automatically)
5. open "RuntimeIPhoneAppDelegate.h"
add to the import lines:
add after " @ interface" the following
AVAudioPlayer *audioPlayer; // Plays the audio
after the next Bracket } add this:
@property (nonatomic, retain) AVAudioPlayer *audioPlayer;
6. open "RuntimeIPhoneAppDelegate.m"
add the following line in the "didFinishLaunchingWithOptions" after the line "[[UIDevice currentDevice] ..."
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:NULL];
that's it! - hopefully you're golden and can now create music or streaming apps with mmf!