This trick applies to the Apollo music player bundled in CyanogenMod custom ROMs.
I have not yet tested this one with any other version of Android or CyanogenMod versions.
In the Android KitKat version Google has replaced the stock android player with the Google music player.
When you are on your lock screen while listening to music, then the lock screen will be looking quite as the following.
[Music player interface on your Android device]
The lock screen music interface gives you, previous, play or pause, next, and the track name.
The timing bar of the track is missing, so you cannot seek the music to forward or backward while stayong on your lock screen.
If you want to seek the music to a forward or backward time of the track then you have to unlock the phone and open the music app and seek the time.
But that is not true completely.
This trick shows how to seek the music bar at your lock screen itself.
When you are on the lock screen while your music is playing or even stopped, then there may have play/pause music soft button respectively in between the previous and next soft buttons.
Now press and hold the play/pause soft button for a while and you will see the seek bar.
That's all... Keep rocking with InfySim.
[Music seek bar on your Android lock screen]