Anyone know how I can get the audio player widget to stay on the lockscreen?

I use the default player and it appears on the lockscreen when I have something playing, but usually disappears once the player has been paused and the screen has timed out.

I read that some apps can be put on the lockscreen, but despite extensive googling, I can't find anything that tells me how this is done.

Feeling a bit of an eejit! Any help gratefully received.