If you’re just getting chords under your fingers, this is going to be the easiest complicated chord progression you’ve ever learned. It’s a one finger shift, and we do it twice. So what’s happening here?
We’re in the key of A minor, and this is the only chord where I’m actually playing the root. That’s a B minor 7 with a flatted fifth, and with the flip of a finger, this structure which looks like a B diminished chord is actually functioning as an E7, even though you don’t hear an E. It’s another case of function over structure, and it primes your ear for an A minor, and I don’t even need to play the A, because you kind of hear it without me even touching it.