Building Chords from Scales - How to Know Which Chords are in the Key

Why does this progression appear in so many popular songs? What about this one? Is this a coincidence? Is there a reason why songwriters are so drawn to using the same chord progressions all the time? If you know anything about music theory, you'll know that there's an Let's discuss. Hi there and welcome to Music Dunes. If you're returning, welcome back. I appreciate you. If you're new here, this channel is dedicated to all things music, music theory, and music history. This video is part of a series I'm making that explains all of the basic fundamentals of understanding music and music theory. So if you're interested in learning how to read, write, or even just better understand music, be sure to check out some of the other videos on this playlist. If you are more interested in music history or pop music, I've got you covered. I cover lots of different topics to do with various parts of western music, so be sure to check out some of my other playlists. In the last part of this series, we discussed the concept of major and minor, how to build their scales, and how to build basic triads. If you're unfamiliar with these concepts, I suggest going back to watch that video, which I've linked here in the i and down below. But for a super quick review, we talked about intervals and how they form the chords and scales that we use regularly. Intervals are constructed using half steps and are essentially used as a unit of measurement in music. We discussed that a chord is a group of notes played simultaneously. The most basic kind of chord is made up of three notes, and it's called a triad. Scales are a sequence of notes in a particular order. These are the intervallic patterns of major and minor scales and triads, both of which we'll be using today. If you're new here, I also made some visuals that are free to download and can help you on this journey. They're linked below as well. The major and minor patterns are as follows. Today, I also want to introduce two more types of chords, diminished and augmented. To make a chord diminished, you simply take a minor triad, we'll call it 1, b3, 5, and you lower the fifth by a half step. So a diminished triad is root, b3, and b5. It's also commonly referred to as minor b5. This b5 interval is what's called the tritone, which is three whole steps. There's a lot of lore surrounding the tritone interval, which Adam Neely does a great video on. I'll link that below if you're interested. Diminished chords can be written a few different ways. As a minor with a flat 5, like so, a chord symbol with a dim added, or it can be a chord symbol with a small circle added, similar to the one used for degrees Celsius or Fahrenheit, like so. The augmented chord is a similar idea, except this time take a major triad and raise the fifth by one half step, making it 1, b3, 5. An augmented chord is designated by adding a-u-g to a chord symbol, or adding a plus to a chord symbol. With all of that out of the way, let's break down how we can know what chords are in the key by using scales. Let's start with a major key. If you're not familiar with your triads yet, it'll be helpful to have those charts I made in front of you. We'll use the key of C major. I'll first lay out my major scale. Notice how I've numbered each note on the bottom. This is important. To build these triads, which again are made of three notes, I'm going to do what's called stacking thirds. All this means is that I'm going to stack my chords using every other note. Allow me to demonstrate. In the C major scale, if I start on C, I'm going to skip D and F and stack C, E, and G. As we learned the last time, this is our C major triad. I'm going to write that here. Now we'll move on to D. Start with D, skip E and G, and we have D, F, A. This is a D minor triad. The pattern continues. E, G, and B is an E minor triad. F, A, and C is an F major triad. G, B, and D is a G major triad. A, C, and E is an A minor triad. And our last chord is a special one. B, D, and F make up one of those diminished triads we were talking about earlier. This pattern we've just laid out will apply to every single major scale. What that means is these chord qualities apply to every major key. So in a major key, the 1, 4, and 5 chords will always be major, the 2, 3, and 6 chords will always be minor, and the 7 chord will always be diminished. A quick side note. When talking about modern music theory, people very often use Roman numerals to designate chords and Arabic numerals to designate singular notes. Roman numeral minor chords can be designated with a lowercase m, a minus sign, or by making the numerals themselves lowercase. This would be something you'd see to describe major key chords. Anyway, I'll show you this pattern again, but by working backwards. Let's use the key of G major, starting with the G major scale. The 1, 4, and 5 chords will be major, the 2, 3, and 6 chords will be minor, and the 7 chord will be diminished. This is correct, I guarantee it. But let's double check the work by using that triad visual. The notes of a G major triad are G, B, and D. A minor is A, C, and E. B minor is B, D, and F sharp. C major is C, E, and G. D major is D, F sharp, A. E minor is E, G, B. And F sharp diminished is F sharp, A, and C. Hopefully this is all making sense so far. What this information tells you in terms of playing music is that these chords are the ones that will make the song sound like it's in the major key you want to be in. So if you want to write a song in G major, you can more or less play these chords in any order you please, and they'll sound correct. The diminished chord in particular is a little bit harsh, so while it's not incorrect, it's not very commonly used in pop music. Here are some common chord progressions that are used in major keys. If you're someone who listens to a lot of music, I'm willing to bet that you recognize these progressions from at least one song. As far as exploring why these progressions are so common and more specifics of chord function within a key, that's going to be a separate video. For now, we'll move on to minor key points. When it comes to understanding natural minor in general, it's best to learn it as it compares to its major counterpart. We talked a bit about this in the last video. This is the concept of the parallel minor. Let's start with C again. Here's the C major scale. I can make this scale C natural minor with three simple adjustments. I'm going to flat the third, sixth, and seventh degrees of the scale, which simply means I'm going to lower each one by a half step. So E becomes E flat, A becomes A flat, and B becomes B flat. Here's my C natural minor scale. Just like I did with the major scale, I can use this natural minor scale to figure out which chords can be utilized in the key of C minor by stacking thirds. My first triad is C, E flat, and G. This is a C minor triad. Next is D, F, and A flat, which is a D diminished triad. E flat, G, and B flat is E flat major. F, A flat, C is F minor. G, B flat, D is G minor. A flat, C, E flat is A flat major. And B flat, D, F is B flat major. Again, this pattern laid out here will apply to every natural minor key. So if you know your scale and this minor key pattern, you can simply fill in the blanks. So the chords in the key of G minor are G minor, A diminished, B flat, C minor, D minor, E flat, and F. When people write in a minor key, they'll keep the minor one chord as the central focus. So when the chords resolve, they do so to that minor one chord. Again, we'll talk more about chord functions in a later video. Oftentimes, songwriters will intentionally leave out the flat three chord, because it's also the one chord in the relative major. This removes any confusion as to whether or not the key is minor. Additionally, for reasons we'll get into in a separate video, the five chord in the minor key can also be major, depending on how it functions in the progression. The short answer for this is that the minor five chord sounds weak in comparison to the major five chord. I'll give you a quick comparison now. All that said, here are some common chord progressions in minor keys. This video is just scratching the surface when it comes to building and understanding chords, but if you're just starting out, I encourage you to take these concepts really slow and internalize each of them to the best of your ability. We're going to get more into these things as we go along. But it's going to be harder to understand later down the line if you're not super familiar with your fundamentals. Again, there are free visuals I've linked down below to help you do so. Please feel free to ask any questions in the comments and I'll do my best to answer them. I hope you're enjoying this series so far and you've learned a thing or two. More content to follow, so don't forget to like and subscribe if you haven't already, and thanks for watching!