They Played Themselves
If you still tune into the radio, you’d know that stations run contests all the time for their listeners. In fact, sometimes the prizes are pretty awesome. The OP’s local radio station had a contest where you call in when they play the same artist back to back to win a prize.
What they didn’t realize was that their website had a “now playing” and “up next” feature. So, the OP’s girlfriend knew exactly when this was going to happen and would start calling in before the second song even started. Thanks to their quick thinking, they won tons of prizes ranging from concert tickets to a laptop. Imagine that!