Why are there different keys in music? Thursday Theory with Thtuart!

Indexé : 2026-05-21

[00:00:00][music] >> What is the point of of keys in music?

[00:00:07]Why are there different keys? This is one of those questions that no one has asked me to answer. I'm actually not sure anyone has even asked this question of themselves.

[00:00:19]The reason I am making this video is because this is a question I asked myself when I was younger and I was just starting to play music. So basically first of all, what is a key? A key is just a collection of notes that sounds good together. It's a little bit more nuanced than that, but like the key of C major is just those notes. Those notes sound good together. That's the key of C.

[00:00:46]Okay, then what's okay, what's the key of D flat then? Well, it's another just group of notes that sounds good together. Here's D flat.

[00:00:57]There it is. Okay, but you ready for this? Here's the the crux of the whole thing. Look, okay, I'm going to first I'm going to get those notes out of your head.

[00:01:14]All right, now I'm going to play either the key of C or the key of D flat and you're going to tell me which one it is, okay? You ready?

[00:01:23]>> [music] >> Which one was that? May If you have like perfect pitch or like a really good tonal memory, you might remember. But they sound they sound the same. C Oh, C. And then here's D flat.

[00:01:36]I messed up.

[00:01:39]It's like all of the notes in the key of C and all of the notes in the key of D flat have the exact same relationship to each other. All of the chords in the key of C have the same relationship to each other as the chords in D flat have with each other. So what is the the of different keys? Like if you if if you play a song in the key of C and then you turn around and you play the same song in the key of F, like >> [snorts and clears throat] >> they're still going to sound like the same song. They're still going to have the same emotional impact overall.

[00:02:12]They're going to basically be the same.

[00:02:14]So, what is even the difference between keys and why do we have all of these different keys? I gave this some thought and I would like to answer the question for you right now. So, first of all, all of the different keys just kind of exist. Like like as a human kind, we have decided that >> [music] >> these notes sound good together. So, okay, great.

[00:02:39]Even if we only ever made music in the key of C, all of the other like pitches would still exist. Felt like felt like I swore, but then I was like, "Did I swear?" No, I didn't. I said pitches.

[00:02:54]I got 99 uh keys and um pitches.

[00:03:01]How was that?

[00:03:03]How was what?

[00:03:05]Didn't you say Didn't you say you had like an appointment? How'd it go?

[00:03:09]No, that was last week. Oh, okay, sorry.

[00:03:11]I misunderstood. What I'm saying is let's pretend that all of us in the world were like, "We don't need all these other We don't need this because we have this.

[00:03:23]We're just going to write all of our songs here."

[00:03:28]And let's just be Let's not worry about the other ones.

[00:03:31]We could do that.

[00:03:33]But all of the other keys still exist.

[00:03:36]They're still there. Those frequencies are still part of the universe, so we might as well use them, right? That's That's my reason number one for why multiple keys exist and we use different keys.

[00:03:46]Another one is because as we all know, there there to be change and variety.

[00:03:52]So, even though you could take any song that you wrote in the key of C and change it to the key of E flat and it would still sound like the same song, we we do sometimes want to have a key change within a song. We're going from one key to another. But, also if we're playing multiple songs in a row, we don't want them to all use that [music] same set of notes because then it would just sound like every every song would start sounding more and more the same. Uncle Stuart, I don't think you should have made this video.

[00:04:22]Shut up. Sometimes I get to do things I want to do.

[00:04:26]Uncle Stuart, I'm pretty sure you choose all of the topics and all of the songs.

[00:04:30]So, I think you only do things that you want to do.

[00:04:36]I literally didn't ask you.

[00:04:38]I did not ask for your opinion.

[00:04:41]My like 11-year-old nephew got a book and it said, "How to be a responsible 11-year-old?" And it said we flipped through it and it said, "Think to yourself, does this situation need an opinion right now?"

[00:04:54]And like that's not just for 11-year-olds. That's for 18-year-olds, 24-year-olds, 36-year-olds, 58-year-olds, and 97-year-olds.

[00:05:06]Um Okay.

[00:05:10]I think we're done. Even though each key is basically just a clone of every other key and they all like have the same overall emotional impact and the same overall sound, when you go from one key to another, it does create variety. So, that's helpful, right? Hey, here's another thing. On different Well, okay. It is my belief that the key of C minor is not inherently sadder or darker than the key of E flat minor. I do not believe that to be the case. I do not believe that there's like lower keys and higher keys and you want a lower key for this and a higher key for that.

[00:05:48]I don't believe in that. I think that the relationships of the notes in one key are exactly the same as the relationships between the same relative notes in a different key.

[00:05:59]But on different instruments, different keys sound quite a bit different. On acoustic guitar, for example, the low E has this very [music] distinct sound.

[00:06:10]So, something that's in the key of E minor >> [music] >> is going to sound very different from a song that's in the key of E flat [music] minor.

[00:06:21]That was a pretty like jarring difference just then.

[00:06:25]On piano, there going to be other parts of the keyboard where the notes start sounding really low and boomy. For a voice, for like every human being, every key is going to be a little bit different because one person might be straining for a note while the other person can't hit that note at all. While another person can easily hit that note and have it sound really clean and clear. So, that's another reason.

[00:06:50]Which brings us to the final point, which is I think the the biggest argument for keys existing is the human voice. Because a song like yeah, okay, you know, cuz people have different ranges. Man, last night this seemed like such a good idea, but now as I'm recording it, it just isn't even anything.