Nothing much happening here, just Scotty, Chekov, and Freeman sitting down to some drinks while on shore leave. Unfortunately, the bar also contains a dozen or so Klingons (but not enough to constitute a swarm).
Korax, one of the Klingons, attempts to goad the off-duty officers into a fight, but Scotty tells them to keep their cool. Unfortunately, Korax ultimately hits a nerve with Scotty when he insults the Enterprise.
This puts Scotty over the edge; he decks Korax and sets of a massive bar brawl. He also kicks off another glorious example of 1960s television scoring. I mentioned previously how much I enjoy the instrumentation and funky rhythms of the TOS scores. All of that is on full display here—choppy, disjointed musical phrases in the woodwinds and brass (including what sounds like either a tenor or baritone saxophone), trilling flutes in the more humorous passages of Cyrano Jones taking advantage of the melee to help himself to some free drinks, and some wonderfully expressive percussion passages (the interplay between the snare drum and toms is particularly delightful).
The cue ultimately builds in climbing brass and xylophone as Jones triumphantly toasts the crowd with one last stolen drink, concluding one of my favorite cues in all of TOS.
For a perfect illustration of the deficiencies of 90s Trek scoring, simply listen to Dennis McCarthy’s take on this scene in the otherwise magnificent “Trials and Tribble-ations.”