One thing I see somewhat disregarded sometimes when it comes to analyzing Undertale is the fact that Toby Fox is a musician. Not only are there countless ideas and emotions conveyed throughout the soundtrack of the game, but Toby actually wrote all the music before even beginning to code. (Source) What does this mean?

The music from the soundtrack can actually reveal some very important things.

Toby wrote the story for the game as a musician. Every motif you hear, all the titles, everything holds relevance. With this knowledge, there has been a few passages in Toby’s songs that are very… VERY fascinating to me from a musical standpoint. The most peculiar to me, by far, is the final eight measures of Last Goodbye.

This is the final moment, the end of the opera, the huge finish. But instead… Toby goes for a much more simple, quiet ending—just a simple melody and counter point that holds the likeliness of the opening song: Once Upon a Time. Upon my first playthrough of the game, these last few notes felt… Unsettling to me, for lack of a better word… But why? What is so strange about the notes Toby chose?

It’s because Toby chose to not end his bass voicing on tonic. The big, final, “last” goodbye… It doesn’t feel very final, does it?

Right now, I’m sure there are probably some of you scratching your heads. What is tonic? Well, allow me to explain. In music theory terms, tonic is the first step of a scale. It’s the keynote of the key you’re in. Almost ALL songs end on tonic, using what is called an authentic cadence. If we go by the key Toby uses in Last Goodbye, the last note should be a B—which he does! But not in the bass.

“What’s the big deal?” I can hear you asking. Well, in order to really drive the ending of a song home, you end on what is called a I chord. The most authentic sounding way to do this is to have the tonic sounding in your bass voice (the lowest voice) and your soprano voice (the highest voice). As I said before, nearly all songs end this way. I’m serious.

What’s even stranger than not ending on tonic, however, is the note he did choose for the final chord. It’s a C Natural, which is very strange to end on in the key of B Major, since diatonically it would be a C# in the key. So the last chord of the “last goodbye,” as we part ways with our favorite goatbro Asriel, is made up of a B and C, two notes a half step apart. Now, I’m gonna ask anyone that has a piano nearby: Go play these two notes together. Go ahead. You don’t even need to be a musician. Here, I’ll even show you the notes.

Doesn’t sound very good, does it? These two notes are a Major 7th/Minor 2nd apart, which is very, very dissonant when played together at the same time (which means it sounds bad). But Toby is a sorcerer, and he manages to make even these two very strange notes sound good.

And yes, the song doesn’t sound bad. It doesn’t sound bad at all! But it doesn’t have that final quality to it—it doesn’t feel like this should be the final song we hear as we finish such an incredible, emotional game.

Which brings us to the big question: Why? Why end the last song like this?

This game isn’t done yet. Toby still has another song planned, or perhaps… Maybe he can just finish one of his songs that he intentionally… cut off?

Yes, the song that plays during the credits! It got cut off, remember? It was leading up to that nice, final resolution! The happy ending! The End! The End… Weren’t we about to see those very words before…?

So not only are we interrupted before seeing The End, but our song got cut off! That was supposed to be it, right then and there! Had it ended… I suspect it might have looked something like this…?

This was the most finished I could get it to sound… So there’s obviously some modulating shenanigans going on to end up in the key of Gb major, which I would love to explain, buuut…! This is an Undertale blog! Not a music theory blog… As much as I would love to dig into it, there’s not much point in explaining, but this would end on tonic because Toby does some chromatic movement to change keys.

I can also hear you guys wondering… What about Goodnight? The very last song on the soundtrack that was never even in the game! Well… I transcribed it… And it doesn’t seem to end very finally, either…

Those roman numerals I wrote in is the chord—a ii⁷chord… Which, uh… Is sadly not a I chord. Which does make me a little disappointed. I thought for sure this was gonna be the song to finish the game off once Toby added that fabled “fourth ending” we’ve all been wanting. I can just imagine it playing during the stay with Toriel ending, but now with Asriel, and maybe even Chara! But it doesn’t sound like a final song to me… It strikes me as more of a transition to something, maybe something happier? I’m not sure…

Anyways, while I try to finish this long rambling post up and we’re still on the topic of music and Undertale, I just want you all to recognize the song that plays when we finally reach The End screen. Memory, Asriel’s theme. Toby could have picked any song, he could have chosen no song! But he chose this song so we would keep Asriel in our hearts and minds, and as a reminder that “There’s still one last person that needs to be saved.”