Mood Beats In RPGs
The two mood beats, gratifications and bringdowns, can land in the roleplaying story form just as they do in films or written fiction. Often however the unique qualities of the roleplaying form change the way they appear.
Gratification beats might be analogous to the moments when the GM tosses in a scene to satisfy the desires of a restless player. You give the guy who likes to fight a gratuitous scrap with kobolds after spending a bunch of time on plot and investigation. The player who likes to chew the fat at length with minor characters gets in some chatting time with the local sword vendor. For the player who digs cultural exploration, you might throw in a chance to poke around in the local temple and witness a colorful ritual.
However, there's an uncertainty principle at play here. In an improvised story that unfolds as a collaborative first draft, it's not necessarily clear what the structural significance of any given beat will turn out to be. Mood beats, more than the others, are defined in the negative-they change the mood without impacting the overall story. As GMs we might introduce elements thinking that we're merely temporizing to keep everybody happy, but then find a way to retroactively weave the kobold fight, the sword vendor's gossip and the local ritual together. In effect what you think of at the time as a gratification beat becomes a pipe beat, retroactively. Likewise with elements either introduced by or built upon by the players.
Extra-narrative moments that change the mood in the room might also be considered our unique form of gratification (or bringdown.) The out-of-character joke during a tense moment fulfills the same emotional purpose as the moment in a horror film where the hero suddenly staggers past a scene of touching normalcy. On the bringdown side, a moment of real-life tension between players generally proves more upsetting than anything that might happen in the storyline.
You might introduce an element out of left field in an attempt to change the mood in the room. In character as a PC, you might focus the attention of clashing players back on the game. As a GM you might throw in some comedy relief, or zip ahead to a fight or other sequence requiring teamwork.
As roleplayers are both artists and audience, they may be switching back and forth fluidly between these roles, changing the mood as they go. The attentive player or GM takes the collective mood into account when deciding what story moments they want to work toward.