The P-value Polka

Lyric copyright by Bret Larget
May be sung to the tune of "Roll out the Barrel" (Lew Brown, Wladimir A. Timm, Vasek Zeman and Jaromir Vejvoda)

What's a p-value?
Test a hypothesis and see.
What's a p-value?
It is the probability,
That a new test statistic,
Would be at least as extreme as the old,
Given Ho is true.
That is what I'm told!