When designing Run Mate’s integration with iPod music library, my main goal was to be a good neighbor in the iPhone OS and to not impose unnecessary actions to start the run. Thus, if you had any music already started — regardless is it playing or paused, it is enough that iPod app with its library is in memory — Run Mate will go along and re-use that.

If that is the case, then when you get to the Sequence screen this is the display you will see if the background music is playing:

With background music is playing, Run Mate shows pause and stop controls

or this one if background music is paused:

With background music paused, Run Mate shows play and stop controls

If you now tap “Start run” that music will be reused.

If you tap the red Stop button, you will effectively clear out whatever playlist is in memory and thus no music will be available to Run Mate, so the screen will change into this:

No background music available, “Pick music” buttons shows up

Thus now you can tap “Pick music” button and the iPhone’s music picker screen will show up:

The standard iPhone’s music picker

Here you tap any number of songs you want (or just tap “Add All Songs”) and then tap “Done”; you’ll be returned to Run Mate which will again show the appropriate interface with play/pause and stop buttons.

I hope this helps.