Things that should have happened

Sometimes--especially when it comes to potential music pairings--there are things just seem like they would've been such a good idea, that they really should have happened. If only...

Happily, I discovered that one of those things that definitely should have happened at some point, actually did. The obviousness and brilliance of it, makes me feel a little embarrassed for ever having doubted it. So, I give you Johnny Cash and Joe Strummer: