So, your song's almost done but you're having problems with the meter. The third line of the second verse sounds good, but it just doesn't match the third line of the first verse. It's so different that you can't just leave it, and it's bugging the heck out of you. You've tried rewriting it a zillion times with different words and word orders. You even reworked the rhyme scheme a couple of times to try and get something new happening. You actually tried changing the story to get a line that would fit. And yet, not one of these options has you any closer to a workable line.

You're out of gas. You've consulted books, played it for all your co-writers, prayed and fasted, and thrown darts at a thesaurus. There's just nothing left to do, is there? Actually, there's always something you can do. There are bound to be word combinations you haven't tried yet. Make a list of the ones you've tried — all of them, every single one. Make a list of possibilities for lines that say the same thing from a different angle. Make a list of other things this verse might say. Cover all the ground you've already covered, take a break, and cover it again. Even Sherlock Holmes didn't always catch things the first time. Make sure you haven't missed something. Oh, and here's a solution you might have missed: If the line sounds good the way it is, why not change the third line of the first verse to match it. Sometimes, it's just that simple.