I just thought I'd create a thread for discussing the score like I did last week along with my observations on it. Feel free to bring up your observations in the comments below.

Kingsmoot

The score in this scene primarily uses the Greyjoy theme 'What Is Dead May Never Die' when Theon is speaking on behalf of Yara. This theme is played once again when Aeron coronates Euron and gives the speech about the eponymous theme. The moment Euron arises from the water the theme changes to a darker version of the theme, which continues and aggravates as he attempts to murder Theon and Yara. This probably going to be Euron's theme from now onward, and I was also anticipating that Ramin would darken the theme for him, but I wasn't sure how. I thought he'd take either 'Pay the Iron Price' or the more battle-like 'Reek'. But it's entirely different, he changed the 3 string notes (the ones which back the 4 notes that we're all familiar with).

Visions & White Walkers

The visions open with the Three Eyed Raven's theme. Both the visions. Albeit the one in the frozen aftermath of the Weirwood tree was a lot more chilling. In the first Dawn Age vision, as Leaf creates the Night King we hear the White Walker arrival theme from 'Hardhome' (The first thought that I had while watching it was that the Walkers were gonna swoop in and attack - just saying). This piece utilizes the industrial "clang" sound first heard in the last section of 'Three Blasts' from the season 2 finale, and heard prominently in 'White Walkers' from season 3.

In the next vision as Bran progresses along the ranks of the wights and appears before the Four Horsemen, we don't get the usual 2 notes that were characteristic of the White Walkers or even the mention of them (Osha to Luwin, Jon to Stannis), in the prior seasons. These two high pitch notes (from 'North of the Wall' primarily) were used in the premiere and every episode related to the Walkers thenceforth in some form, such as in the form of the two lower pitch chords at the end of the new 4 note Walker theme from 'Three Blasts'. It is also heard as backing chords in 'White Walkers' and 'Hardhome' (as soon as the undead attack and wildlings flee). It was surprising that we didn't get these two notes, and I was satisfied as I was wondering how Ramin would move the Walker theme forward, as that phrase had been overdone in the previous seasons.

So instead we get one of the ambient noises, which usually accompanies the two notes, being emphasized upon when the camera shows us the Walkers, even when they arrive in front of the cave. This sounded pretty cool, and it's great to see how Ramin moves their theme forward especially since they're growing closer to the Seven Kingdoms and stronger in power. During the fight with the CotF, we also hear a variation of the 4 notes from 'Three Blasts' that I'd mentioned.

Hold the Door

As Wyllis holds the door and sacrifices his life, we hear a reprise of the Stark theme. This plays out in its full somber form, with a few additional notes at the end(?).

EDIT: As others have pointed out, this piece was probably 'Goodbye Brother'.

This is everything that piqued my attention in my first viewing of the episode.