The two did a song together called Rock 'n' Roll Mercenaries, and I had no idea this song existed until back in June when I saw a music video of the song that my friend made using it. The chemistry between the two works out very well, but John Parr steals the spotlight on the song though. This is the only video I can find on YouTube that has the full 5 minute version of the song:

The version in the song's official music video is too short, and the full version is better.