Did you hear it?

The "fat lady" has finally sung. No, obviously not Katy Perry or Taylor Swift – they are anything but portly – but the fact that the stars have once and for all called a truce means that their "beef" is over. The years-long feud between the A-list entertainers has been resolved, thanks to Perry extending an olive branch - and we don't mean figuratively - to her one-time enemy, Swift.

The two have been like oil and water ever since it was alleged that Perry "stole" backup dancers from Swift's tour, leading Swift to blab to Rolling Stone that her latest song lyrics were based on the petty event. That was in 2014 and it took four years for these "grown-ups" to get over it.

They "threw shade" at one another through their songs, videos, and in interviews, and repeatedly aimed to one-up the other with strategically-timed music releases, "squads," and "diss tracks." Perhaps the two kept it going for the attention, but with all the evil in the world, one would think millionaire musicians would be grateful for being young, rich, and beautiful. But like Swift sings, "haters gonna hate."

Maybe Perry was acting on her New Year's resolution nearly half a year in to apologize and mend broken fences. Just in time for Swift's "Reputation" stadium tour, she sent Swift the olive branch along with a nice note in the hopes that Swift would let bygones be bygones. And doggonit, Swift was finally ready to forgive. But like the rest of us, after four years of this nonsense, it will be hard to soon forget.

Then again, we can thank Perry and Swift for duking it out, so to speak. Without their sensational squabble, we would have never been blessed with "Bad Blood" or "Swish Swish." The singers' tribulations turned into some pretty catchy tunes. Go figure.

Now that these gals are on their way to a newfound friendship, take a walk down memory lane with pics of their relationship and musical journey. And you can bet your bottom dollar that a musical collaboration is in the works.