Learn music theory in 29 minutes

This video is sponsored by Pianote. Today I'm going to teach you as much as I can about music theory in 29 minutes starting with our 12 notes of western music which are A, A sharp, B, C, C sharp, D, D sharp, E, F, F sharp, G, G sharp and then we go back to the beginning again we're back at A. A again, A again. It keeps repeating up. Why do we only use the first seven letters of the alphabet rather than labelling the entire keyboard with the whole alphabet? Well it's because after 12 notes we get to a note that is an octave above the note we started on. These are both referred to as A but they are different pitches. This is A 220 hertz and this is A 440 hertz. One's obviously low and one's obviously high. They're not technically the same pitch so why do we give them the same note name? Well it's because notes that are an octave apart are so compatible with each other. The frequencies blend in such a perfect way that we interpret them from a functional point of view as the same note. Sounds the same as... We can hear that it's the same melody, it's the same notes but one was lower and one's higher and as you might have noticed from the frequencies we had there 220 hertz, 440 hertz. Notes that are an octave apart by definition have double the frequency of each other and that is effectively what makes them sound so compatible because their frequencies are perfectly slotting together. So we have these 12 different notes that repeat up the keyboard and the white ones as you can see are named after the first seven letters of the alphabet. The black notes actually have two different names each. I initially refer to these as their sharp names so this is A sharp but we can also refer to this note as B flat. Now why and when you would refer to a note by a sharp name or a flat name is something that if you're new to music theory you shouldn't worry too much about. They are both valid names. There are certain contexts where you might want one over the other but you don't need to worry about that right now. The way to remember the sharp and flat name is here's A. If we want to go up, we want to make it sharper, pointier, we go up the musical keyboard, up in pitch to get to the sharp. It's become sharper and we could do the opposite. If we had this B here and we wanted to make it flatter, we wanted to go down, down in pitch, we get B flat. It's gone down. So that's how we name the black notes. They can either be the sharp of the note to their left, A sharp, or the flat of the note to their right, B flat. So that's our 12 notes but what if we played notes together in a stack like this? Well this is what's called an interval. If we have two notes together we have an interval. The interval is obviously referring to the gap, the interval between those two notes. We already had one interval in which was the octave. This interval I played here is what's called a minor third. We can have two different types of thirds in music theory. This is the minor third which is effectively three semitones. One, two, three. Or we could have a major third which is four semitones. One, two, three, four. Like that. Now the best way to think about and compare different intervals like the is to think about them in terms of the smallest interval we have on the keyboard. The gap between any two notes that are absolutely next door to each other. This interval is called a semitone. It can also be called a half step or a minor second but we're going to call it a semitone. That's a semitone, the gap between two notes that are right next door to each other. So it could be these two, it could be these two, these two. Or we could have a which is two semitones. So the gap between notes that are two notes apart. But the reason we use semitone as a good sort of currency for comparing other intervals is because every interval can be referred to by how many semitones it contains. A minor third, for example, contains one, two, three semitones. And a major third contains one, two, three, four semitones. So it makes it really easy to compare the difference between one interval and another. Now the thirds are some of the most important intervals in western music because it's how we build chords. Chords are when we have three or more notes stacked together like this and they create this sense of what's called harmony. When the notes are sticking together in such a way, combining together, that we get the sense of one unit together. But all they are is a stack of notes, a stack of intervals. A major chord, which is what I'm playing here, is a major third, four semitones, and then a minor third, three semitones. And that's true of every single major chord. If I take this major chord, which is C major, we can see that we have a major third, one, two, three, four, and we have another third on top and this one's a minor third, one, two, three. So to get any major chord you like, you can think about it in terms of those intervals and you can even boil it down to how many semitones you need to move from your starting note. So for example, if we wanted a D major chord, we could take the note D and go up four semitones, one, two, three, four, and then we go up three semitones, one, two, three, and we get our D major chord. That applies to any major chord. That's the definition of a major chord, a major third and a minor third. Another very common type of chord is a minor chord, and a minor chord is actually the opposite intervals. Rather than having a major third and a minor third, like we did in the major chord, we have a minor third and a major third. It's switched the other way around. So if we wanted C minor, for example, we start on C and we go up three semitones, and then we go up four semitones, and we get C minor. Of course, the other way to get a minor chord is if you already know what the major chord is, so for example, C major, to turn that major chord into a minor chord, you just take the middle note, which we refer to as the third, and you lower it down and you get the minor chord. Now, major chords and minor chords are what we refer to as triads, notes that are comprised of three unique notes, and there are other triads we can use beyond major and minor. For example, a diminished triad. A diminished triad is the interval of a minor third and another minor third, so we can think about it as three semitones and then three semitones, and also another type of triad is this chord, an augmented triad, and just like how the diminished triad was a minor third and then a minor third, the augmented triad is the opposite. It's a major third and then a major third. One, two, three, four. One, two, three, four. So you can see from that we've got our four essential types of triad by stacking the minor and major thirds in different combinations. This is why most harmony in western music is referred to as tertiary harmony, tertiary referring to thirds, because we stack almost all of our chord types using these thirds, and that's true when we go beyond just triads. So of course a triad is a three-note chord, like a major chord, but we could have a four-note chord by just adding another note on top. This is a seventh, a C7 chord. Now, there are a few different types of seventh chords. The C7 is actually short for what we call C dominant 7. If you just see the symbol C7, the word dominant is effectively implied. We don't have to write that. So that's a C dominant 7, where we've added a minor third, three semitones, on top of a regular C major chord. If we were instead to add a major third on top of our major chord, so here's our major chord, here's our major third we've added on top, four semitones, it gives us a different type of seventh, a major seventh chord, C major 7. So we can have C7 and we can have C major 7. We can also have sevenths built from a minor triad instead. If we have a minor triad, this is C minor, and we go up a minor third from the top of that chord, we get a C minor 7. So you can see the symmetry there. If we had a major chord and we went up a minor third, we get C7, and if we get a C minor chord and go up three semitones, we get a C minor 7. Kind of makes sense, right? And we could also, from a C minor chord, go up a major third and get a C minor major 7. Quite an unusual sound, but quite an interesting, mysterious sort of chord. So I know we're against the clock here, but I'm just going to stop the timer there for a second to tell you about today's sponsor, which is Pianote. 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So we've talked a lot about chords now, we're against the clock, so let's move on to scales. Scales are another very important part of music theory. The reason we learn scales is mainly because it's almost like pre-learning other songs that you might encounter. So many songs are based on, or are based on, a variation of the major scale, that by learning this pattern of notes and getting your hand used to moving around those notes, you're going to make your life so much easier when you learn songs later on that use that scale. Another reason why we might use a major scale is because it can allow us to write or even improvise our own little song. If you wanted to take a solo, a keyboard solo, or a guitar solo, or whatever, you might use a scale. So the major scale is essentially the most important scale because not only is it the most widely used scale in western music, but we think about a lot of the other scales in western music by comparing them back to the major scale and looking at how they vary from the major scale. To get any major scale you like, you can use the same formula regardless of where you're starting. So this was our C major scale. Of course on the piano it's just all the white notes so that's a really good way of remembering it. But we might want to use a different major scale. We might want to know the D major scale for example. Well we can use the formula and how we apply that formula is we get the note we want to start on, in this case D, and we go tone, tone, semitone, tone, tone, tone, semitone. That's the formula of every major scale. It doesn't matter which major scale it is, it will have that pattern of tone, tone, semitone, tone, tone, tone, semitone. So for example if I wanted to play an E flat major scale, well we'd have tone, tone, semitone, tone, tone, tone, semitone. So that's the major scale but another scale you've probably heard of is the minor scale. And the thing is about the minor scale is there's technically a few variations of it but the main type of minor scale is what we call the natural minor scale. And that just so happens to be all of the white notes but starting on A. So we said before that the C major scale is all of the white notes but starting on C. Well A minor is all of the white notes but starting on A. This is the A natural minor scale. The natural minor scale is exactly the same as the major scale apart from the third degree has been lowered, the sixth degree has been lowered and the seventh degree have been lowered. So this is our A major scale. You can see that it usually has a C sharp, an F sharp and a G sharp. But to turn it into an A minor scale we lower the third so we don't have a C sharp we have a C we lower the sixth so we don't have an F sharp we have a F natural and we lower the seventh so we don't have a G sharp we have a G natural. And that's our minor scale and as I'm sure you're familiar the minor scale has a more sort of melancholic slightly darker sound than the major scale does. So that's the natural minor scale but as I mentioned there's other variations of the minor scale as well the main two being the harmonic minor and the melodic minor. The harmonic minor is exactly the same as the natural minor but the seventh degree has been raised back up to where it would be if we were in a major scale. So C natural minor would have B flat as its seventh note and C harmonic minor would have a normal B, a B natural as its seventh note. The melodic minor changes yet another note back to where it would be in the major scale. The melodic minor is like the harmonic minor but also has a raised sixth degree. Its sixth degree has gone back to where it would be in a major scale. So the melodic minor is almost identical to a normal major scale apart from the third note has been flattened. If you'd like to learn more about why we have these melodic and harmonic variations of the minor scale I've got a video on each of them. So that's the minor scale but let's look at some other common scales the pentatonic scales. The pentatonic scales are effectively simplified almost foolproof versions of the regular major and minor scales. The major pentatonic scale for example is just like the regular major scale but the fourth and seventh notes have been removed leaving us with just five unique notes. And the minor pentatonic scale is just like the natural minor scale but the second and sixth degrees have been removed once again leaving us with just five notes hence penta. Now the particular two notes that get removed when we turn a C major scale into a C major pentatonic scale are not random. These two notes have been removed because they mean that there are no longer any semitones left in the scale. Semitones can be quite dissonant you have to sort of pay attention to when you play them because if you play them at the wrong time it could clash. But because we've removed the semitones from the scale as I said before it sort of makes the pentatonic scale foolproof. You can play its five notes in whichever way you like and not really have to worry about any of them clashing. And of course I've got a video on pentatonic scales as well so if you'd like to learn more about how this foolproof scale works then check that one out. But the last scale we'll look at in this video is the blues scale which is basically a variation of the minor pentatonic scale. The blues scale is exactly the same as the minor pentatonic scale apart from we've added in the flat fifth degree of the scale as well. And adding in this flat fifth gives it a sort of bluesy flavour. So earlier we were talking about chords like major chords, minor chords. Typically when chords are used in a song they're strung together into a pattern known as a chord progression. And the thing about chord progressions is that they sound the same regardless of what key that we're in. For example the chord progression C, G, A minor, F sounds the same as the chord progression D, A, B minor, G because they are the same chord progression just played in two different keys. In both instances they are the chords built on the first note of the scale, the fifth note of the scale, the sixth note of the scale and the fourth note of the scale. So we could refer to them as the chords one, five, six and four. These numbers are referring back to the major scale. And when we're talking about chords in terms of numbers like this we don't use typical Arabic numbers to label them. Instead we use Roman numerals. Uppercase Roman numerals means it's a major chord and lowercase Roman numerals mean that it's a minor chord. Although do bear in mind that some people use a different system where they're all in uppercase and minor is instead indicated by a little m. And the thing about chord progressions is that despite being in different keys the same chord progressions are used time after time in different songs. So it can be really useful to be able to recognize these chord progressions and describe them abstracted from the key that they're actually in. So rather than referring to the chord progression as C, G, A minor, F, if you think about it in terms of one, five, six, four you can better understand how that chord progression has been used in different songs. Now the last topic I want to look at before our 29 minutes is up is how to read notation. And I'm obviously not going to teach you how to sight read in the next few minutes but I'm going to teach you the essential basics of how to understand what's written on notation on sheet music. So the most important aspect of notation to understand is the note values, the different symbols that we might get placed on these lines. The lines themselves are called the stave or sometimes called the staff and there's five lines and on those lines will be placed these different notes. They have different names depending on which country you're in and I actually went through that in this recent video of mine but today I'm going to use the American terms for describing these notes and I'm going to show you a little trick for how we can see how these different note values are related to each other. So we'll start with the longest note value that we have in modern notation which is the whole note, the one that looks like a potato like that or an American football is this round note and it's worth four beats. A beat is effectively what you would tap your foot to when you listen to music. A bar of 4-4 music has one two three four four beats one two three four I'm counting the beats so a semi grave would last four beats one two three four one two three four like that. If we wanted a note that was worth half that value we just add a stem to our little potato and we get a half note which is worth two beats one two one two one two like that. We can half it again by colouring in our potato so we now have a black potato which gives us a quarter note one two three four it's just worth one beat each. If we wanted a note that was worth half of that again we now add a little flag to the top of our stem and that gives us a eighth note one two one two one two so you can see we're getting two notes for each beat because they're worth half each and we can go smaller again if we add another flag to the stem we now have a 16th note one two one two because they're worth a quarter of a full beat we fit four in the space of a normal beat the thing I'm counting out loud. Another thing to bear in mind is with eighth notes and 16th notes and anything smaller than that when they're put next to each other on the stave rather than them each having their own individual flag we bar them together to make them that bit easier to read but these are the same note value they're still eighth notes they're still 16th notes but they just look a little bit different. So those are our different note values but what's this thing at the beginning of our stave? Well this is our time signature what we can also refer to as our meter and it tells us how many beats are going to be in each bar of the music. I mentioned in passing a minute ago the time signature of 4-4 which is the most common time signature that we'll get across western music. In the time signature of 4-4 we have four beats in each bar of the music and that dictates how the music sounds. Each time signature has its own sort of sound its own sort of rhythm. 3-4 for example music that has three beats in each bar has what you could think of as a waltz sound. 6-8 has more of a swinging sound. I've done my sentence. And 5-4 has more of an off-balanced odd sound to it. So what do these two numbers in a time signature actually mean? Well the top number is the more obvious one it's telling us how many beats will be in each bar of the music. In 4-4 for example there will be four beats in each bar of the music. After those four beats we'll have this sense of the rhythm and the meter resetting. But what does the bottom number refer to? Well the bottom number is telling us what type of beat will be in each bar of the music. The four here actually refers to quarter notes. If you think of course a quarter is splitting something into four so we use a four to represent that. So in 4-4 time each bar of the music will have four quarter notes in each bar of the music. In 6-8 time there will be six eighth notes in each bar of the music. Now the thing is with time signatures the most important number to pay attention to is that top number the how many beats in the bar. Because that's the one that truly has an influence on how the music sounds. And the last thing you need to be able to read notation and the last thing I'll teach you today in this video is how you actually work out which pitch these notes are referring to. And of course that's to do with where they're placed on the stave, where they're placed on the five lines. Depending on where on the lines or in between the lines we get our notes it's telling us which keyboard note to play, which pitch we should play. Now this depends on what clef we have at the beginning of our stave. The clef is a little symbol at the beginning which effectively tells us what set of notes are going to be on these lines. The most common type of clef is the treble clef otherwise known as a G clef and the reason it's called a G clef is because it's effectively a stylized G and it's resting on this line which tells us that this line is the G and therefore we can use that to work out what all of the other notes are on the lines and spaces. But that's not generally how we try and remember what notes are in these lines and spaces. We instead use these little memory aids and the main memory aid for the treble clef is face. The spaces of the treble clef happen to spell out the word face which means if we put a note, any old note, in this space at the bottom of the treble clef we get an F. If we put one in the next space we get an A and of course the line between F and A is G because that's the note between F and A. Now what you may have noticed there is that by default by placing notes on the lines and spaces of our stave we only get the white notes of the piano. How would we notate a sharp or a flat note? Well there are two ways that we can do that. If we want a one-off B flat in our music well all we have to do to notate that is write a B as usual so a note on the central line of the stave and then put the flat symbol with the little B symbol before it turning it into a B flat and of course remember that even though it's B flat that on the stave it should have the flat before the B because the player needs to see the flat symbol before they play that note. Likewise if we wanted a C sharp note we would notate a C as usual so the third space up on the stave but then put a sharp before it. C sharp. The other way though that we can notate having these black notes is what's called a key signature and as you can imagine that's to do with the key of the piece of music. The key of a piece of music is more or less where the centre of gravity is in that piece of music where it wants to resolve back to and that is usually to do with which major scale that that piece of music is using. So for example a piece of music in the key of D major will be using the D major scale. A piece of music in D major will therefore use lots and lots of F sharps and C sharps because those notes are in our D major scale and it won't use very many if any F naturals and C naturals because those notes are not in our scale of D major and therefore rather than every time an F or a C comes up in our piece of music putting a little sharp before it we can instead save ourselves a lot of effort and make the music look a lot easier to read by putting those sharps the F and the C sharp at the beginning of the piece of music and asking the player to sort of memorise them. This is called the key signature. Rather than writing the sharps all across the music as what are called accidentals we instead place them at the very beginning of the piece of music telling the player to always play an F sharp and always play a C sharp unless otherwise specified. If we did want a normal F what was called an F natural instead of an F sharp well because the key signature at the beginning of the music has told us that every F by default should be an F sharp well now we have to put a little natural symbol a little natural accidental before the F telling the player that this F will be a normal F natural. The sharps in the key signature have been placed on the relevant space or line for the note that they're meant to be sharpening so this sharp is on the F line at the top and this sharp is on the C space in the middle now something to bear in mind is that although we've only got a sharp on this F up here on the top line even if we have a note notated in the bottom space which is also an F that will also be sharp if it says one of the Fs is sharp it means all of the Fs are sharp and if it says one of the Cs is sharp then it means that all of the Cs are sharp by doing it that way it means that each key has a unique number of sharps or flats so the only key signature that has two sharps is the D major key signature this one here which is really advantageous because once you've memorized your key signatures you can then just glance at the number of sharps or flats and instantly know which key it is without actually having to work out which lines and spaces have been sharpened or flattened. Now another thing to bear in mind is that accidentals so when we put a sharp flat or natural on the bar of music like this they last for the rest of that bar so if I wanted this C to be sharp but this C to be a normal natural C I'd have to notate a sharp here and then a natural here to undo that sharp but the advantage of this of course is that if I want the entire bar to be C sharps then I don't have to put a sharp before every single C I just put one before that first C and then that affects all of the other Cs up until we reach the bar line here. And there we are we have learned as much music theory as we can in 29 minutes. Of course some of these topics I only went over very briefly so if you'd like to go into more depth I've got a whole ton of videos on all of the topics that we talked about today.