Let me show you three methods for finding the key of a song easily and accurately (there's an old joke: easy, accurate and quick, pick any two). Well, the first will be quick and dirty and not very accurate, and the next two are pretty accurate and will serve you well in mastering this simple but highly important skill. You don't need ANY theory to follow along - results guaranteed!

TIMESTAMPS
0:00 Introduction
0:16 What IS a key?
1:06 Another definition
1:56 Method 1 (Quick and dirty)
5:32 Method 2 (Slow and accurate)
10:20 Method 3 (Slow and accurate)