raise up your bat is naturally the highlight of the chapter 3 soundtrack for me. the melody is great, both sets of lyrics are great, the lost girl leitmotif is incorporated beautifully as the chorus of the entire thing, oh and for some reason there's quite a few parts that sound like megalovania and justice from undertale yellow. one of the rare lyrical pieces in deltarune so far, and toby knocked it out of the park (though was anyone expecting otherwise?)
chapter 4 has an even stronger soundtrack in my opinion, with several top-tier songs, but i'd like to highlight the third sanctuary and its ridiculous yet fluid time signatures. the song as a whole has a really driving energy to it, and that 23/8 part. truly the peak of the song. there's like at least three different ways to feel the rhythm in that section and i can switch between all three of them on the fly. the part at 1:47 is also quite fun to follow along with. i like to count it as 12/8, 11/8, 10/8, 12/8, 11/8, 11/8, 11/8, 12/8. has a really nice push and pull feel to it.
to highlight some less popular songs: paradise, paradise has a nice melody, especially at 1:22. as does old wooden rafters, which is seriously low on views considering how good it is. and ever higher is just cheerful and fun, especially the section starting at 1:05.
can we also talk about how masterfully guardian uses leitmotifs from from now on? the main dark sanctuary leitmotif appears in a bunch of different forms. first the narrower, darker-sounding version associated with the titans, extended in a 3-3-3-3-2-2 rhythm. then the original, wider version in its original 3-3-2 rhythm, bringing in a big burst of hope for the "chorus" of the song. (also the guitar that introduces that section is so cool!) then at the end of the song, we pair up the wider intervals with the extended rhythm for a determined feel that's not fully hope, but also not fully despair. absolutely insane how the same leitmotif can be manipulated into taking on three very different tones in one cohesive song.
but that's not even the leitmotif that i find the coolest here. a motif more unique to from now on is transformed into something much different-sounding in guardian. these are the only two tracks i could identify this motif in, and it's kind of hard to even realize they're the same motif at first because the rhythm is quite different, and the two just don't sound anything alike in the context of their respective songs. truly an amazing final boss theme to end off the gameplay of the new chapters.
...man that's a lot of stuff i wrote. can you tell i like the new songs a lot? say what you will about toby TAKING TOO LONG, the final result is worth it!
nice time signature too! actually is it the first instance of 7/4 (or 7/8 depending on how you interpret it) in undertale/deltarune? can't think of anything else off the top of my head, all other weird time signatures i can think of are either 5/4 due to alphys or the second/third sanctuaries