From Writer Unboxed:
It’s confusing. As if there aren’t enough hero’s journeys and snowflakes to follow in putting together your novel, there is also the matter of beats. Commonly used in screenwriting, the concept of beats sometimes creeps into thinking about fiction writing. What exactly are beats, and do they have any utility in fiction?
Sometimes = always in some sorts of formulaic fiction; eg, romance and cozy mystery — most mystery — and quest novels of various kinds.
[Beats are] moments in a story that are plot pivots or emotional shifts. Palpably and perhaps invisibly, the story takes a step. Things change: outside, inside or between people. The story marches forward in a marked cadence. The felt impact of each step is a beat.
This post doesn’t say this, but romance beats are surely the most standardized. The plot of a romance almost always follows a pattern close to this:
a) Set up
b) Meet cute (or whatever kind of meeting; sometimes not cute)
c) We can never make it work
d) Maybe we could make it work
e) Revelation of some obstacle
f) Dark night of the soul: giving up on love
g) One or both protagonist yields something to the other person and the happy ending ensues
So those are romance beats. This post at Writer Unboxed goes on:
What was supposed to be true might turn out to be false. Right could veer wrong. Bad might become good. When doubt arises, hope is dashed, a silver lining is discovered…when there is any emotional shift at all in the minds or hearts of readers, that too is a beat. … Above all, a beat is something that we experience in a moment. It’s a stab of fear, a twinge of shame, a shout of encouragement, a shot at prediction, a tremor of doubt, a punishing verdict, a roar of rage, a tear of grief, a nod of satisfaction, or anything that causes us to feel a way that we didn’t a moment before.
The rest of the post is about the importance of emotional shifts that arise from character (and reader) reactions, not from the plot (or not only from the plot). A pretty decent post, if you’ve got a minute and would like to click through.