Some basic music theory

[jizma]

Keys

When dealing with music you will learn that everything is written in a specific key. Keys can be a major or minor, determined by what scale you use to derive the key. A scale is a group of 8 notes determined by specific intervals from the chromatic scale.


A A# B C C# D D# E F F# G G#

The chromatic scale is every note in the musical world. Don't ask me why there is a lot of physic and mathematics involved. In fact, Pythagoras developed most of this using the Pythagorean theorem.

Instruments themselves have whats known as a native key. The piano for example is in the native key of C, while the guitar's native key is E. Both of these instruments however have a large enough range, a general term for the amount of notes an instrument can play, that they are able to play in any key. They also can play several octaves. An octave is a key or scale played at a higher or lower pitch.



The instruments in Lotr use the Native key of C major. C major is known as the perfect key because it does not contain any accidentals. Accidentals are sharps or flats, they are a semi tone of a natural note. I'll go into more detail when I discuss the chromatic scale later.

Shamelessly stolen while I browsed wikipedia for information. (http://ask.metafilter.com/6444/)

Here is the basic idea in a nutshell. Certain patterns and combinations of notes sound nice together, or make certain effects -- we call these scales and chords. Certain combinations of scales and certain combinations of chords sound better than others -- we call this harmony. For instance, combine certain chords together, and you get music that sounds sad -- we'll call this minor harmony. And if you combine certain other chords together, you get music that sounds kinda happy -- we'll call this major harmony.

Search a bit more, and you'll find that you can make a number of different harmonies that all sound 'minor' in a similar way, it's just that you play them higher or lower on they keyboard. So you give them different names in order to distinguish them, based upon where in the keyboard they lie. This one up here I'll call 'B minor', and this one down here I'll call 'D minor'.

I know that spiel comes across as incredibly condescending, but that really is all there is to it. At the same time, I realise that in isolation, without examples, the concepts I've described above can be quite difficult to get your head around and relate to 'real music', and it doesn't really answer all of your questions. So now you will all watch in horror as I ramble on for five hours about music, to try and give a feel for what 'key' means to a musician.

First of all, you have to realise that if you're writing in a certain key, there are no rules written down someplace that say, "no less than 80% of your notes must be taken from the home key", and "you may use no other chords than those constructed from your key", etc.. Certainly, if you're trying to write in a certain style then you may find that your music does follow rules like this. But that is because the style/period of music dictates conventions about what harmonies are acceptable and which are not, what chords are Godly and which are lewd, and so on. The concept of a 'key' arises from the complex interplay of notes and chords and harmony, not the other way around.

Let's say I'm writing a really simple blues song. If you know your twelve-bar blues, you'll know it goes something like

C C C C F F C C G F C C

(where each letter corresponds to a measure of music, and 'C' means 'C major chord', etc.). Now, I can take that exact piece of music, and 'transpose' it into a different key, say, A:

A A A A D D A A E D A A.

What makes the first piece of music 'in the key of C major', and the second piece of music 'in the key of A major'? How would you tell the difference between them if you were listening to them?

Well, the first thing to notice is that in both pieces, there is one chord that I spend most of my time on. In the first piece, it's C-major, and in the second piece it's A-major. In a very real sense, this is the 'main' chord of the piece. Sometimes this alone can be a good indicator to what key a piece is in -- particularly for forms such as blues, country, and pop.

Another, more subtle thing to notice, is that there is a very specific arrangement of chords sitting around the home chord. In the first case, we start on C, and we go up to F, and up to G. If we call C number 'one', and count up the keyboard, you can see that we use chords 'one', 'four', and 'five'.

Now do the same with the second piece. We start on A, and go up to D, and up to E. If we now call A number 'one', then D turns out to be number 'four', and E is number 'five'. It's the exact same relationship.

In fact, in the vast majority of Western music, these chords, I, IV and V are the most common chords used, simply because they are the ones that sound good when they're played one after another. When your brain hears that relationship of chords, even if you don't consciously realise it, it will be able to pick out which chord is number I, the 'home' key.

It's like if I drew an arrow on a piece of paper, and asked you to identify the point of the arrowhead. No matter which way round I turn the piece of paper, you'll be able to find the point, because your brain understands the relationship between the lines on the paper, even if I turn it upside down, stick it on the ceiling, or whatever. It's just like that with harmony and different keys.

So to answer your question about how your friend can identify a piece of music as being in 'E major', he's actually using two tricks. The first is that, like most of us, he can identify the 'home note'. Secondly, your friend is gifted with 'perfect pitch', which is the ability to hear a note, and identify what letter (C, B-flat, E) that note corresponds to. That truly is a gift, and most people can't do it, but the essential part is that he's identifying the 'home note' of the piece, and that's an intuitive thing that most people can manage quite well.

Perhaps you think you can't do this. Well, put on a piece of simple music, pause it halfway through, and just tell yourself to "hum the main note". You may be surprised at how easily your brain picks out a note to hum. At the very least, you can usually tell whether the piece sounds 'complete' and it could stop there (even if it carries on in real life), or if it sounds 'interrupted' and needs to carry on to go somewhere else.

Try these hastily-edited examples (MP3). In each case, decide whether the last chord/note you hear is the home chord/note, or whether it is some other chord/note. Answers at the bottom of the post.

1. Jupiter
2. Cello
3. Fortuna
4. Thrill

Okay, so how does all this touchy-feely "hearing the home note" stuff apply to real, hard music theory?

Pick up a piano sonata by Mozart that is 'in F major'. If you look at the start of the music, you'll see that the 'key signature' consists of a single B-flat. That B-flat is a signal that the music is 'in the key of F major'. But what does that mean?

Well, really, key signatures are just a notational device. When Mozart sits down to write a piece 'in F major', he'll find that almost all of the B's that he writes down will be B-flats, not B-naturals (or B-sharps!). The key signature is just a way to avoid having to write down all of those 'flat' symbols. Indeed, I could re-write the piece in an entirely different key signature that I've just made up (let's say, one G-sharp and one D-flat), and although I'd have to put accidentals all over the place, and it would be incredibly awkward to read, the actual music -- the notes that are played -- won't have changed. Play it back, and it'll still sound 'in F major'.

So, the key signature can give us a clue about what the 'key' of a piece is, but it is certainly not the end of the story. However, it does give us a useful hint about how we can puzzle out the 'key' of a piece. It seems to be something to do with how often you use certain notes.

For instance, in a simple piece in F major, the notes (F G A B-flat C D E) will be used far more often than any other notes. And likewise for any other key -- if you see a lot of a certain scale in a piece, then that piece is probably written in that scale!

This is why even a solo violin or cello line can have a strong sense of key, and even a strong sense of harmony and chord progressions. Bach especially was a master at creating musical lines that suggest very particular chords, even if those chords aren't specifically being played by any one instrument. Listen to this sample from the double violin concerto in D minor, and notice how, even though all the instruments are playing their own, independent, very complex tunes, there is an incredibly strong feeling of harmony and direction and chord changes.

Bach manages this because his style of music sticks quite rigidly to the 'rules' about what notes are allowed in a certain key, and what chords are allowed to follow other chords. (He doesn't use other accidentals unless he has specifically modulated into a different key for a section of the piece, in which case he uses accidentals to notate the new key that he's in. He practically always ends his pieces on the tonic. His chords are only assembled from notes in the key's scale.) Because of this, your brain can deduce very clearly what key and chords Bach is intending, even though the notes themselves are fleeting.

As you move forward into the Romantic era, with composers like Brahms and Chopin, musicians were beginning to explore the possibilities of dissonant sounds, and complex, sliding, chromatic harmonies. (They will use random accidentals to create the effect of fleetingly slipping into another key for a brief time. They will not necessarily stay in the same base key for the whole piece, and will sometimes start and end a piece in different keys.) This sample from a Brahms violin sonata, for instance, slides through a few keys in a short space of time, and contains several surprising chord progressions. But the concept of a 'home key' is still very much apparent, even if the current 'home key' changes every few seconds! Listen especially to the end of the sample, where some very clear, well-chosen chords bring us back round to the original home key.

It seems that the concept of a home key is crucial to the ear being able to understand a piece of music as distinct from a sequence of random notes. This is why it has endured, and why the ideas of scales, and home notes are found in most indigenous musics. Despite the efforts of experimental 20th century composers, who have tried at various times to write music with no dependence on a particular key or structure of chords ('serialism' or '12-tone music'), have not swayed us from needing a home key to rely on. Indeed, some composers still use these techniques, but usually only as an artistic effect, creating sounds that are dissonant and confusing (for example, the insanely difficult but compellingly exciting Coloana infinita by Ligeti).

I certainly have given a definitive answer to what a key is. I'm not sure there really is one that is applicable to all circumstances. But I hope by jabbering on for a while I've given enough examples of the use (and misuse!) of key to give you a better understanding of what it means to have a key.

Or I've just confused you even more.

Answers.

1. The melody ends on the home note. (Taken from 'Jupiter' from 'The Planets' by Holst. Played by the Orchestre Symphonique de Montréal under Charles Dutoit.)
2. The cello finishes on the augmented fourth note of the home scale! (Taken from the Suite for solo cello No. 1 in G major by Bach. Played by a nameless cellist on the Neon Genesis Evangelion soundtrack.)
3. Although the music finishes on a triumphant chord, and there is a big rest after it, the final chord is actually chord V, giving a feeling of wanting to fall forwards onto the next segment of music. (Taken from 'O Fortuna' from 'Carmina Burana' by Carl Orff. Performed by the Chorus and Orchestra Salzburg Mozarteum under Kurt Prestel.)
4. The last chord you hear is the start of the next 12-bar cycle, and it is indeed the home chord. (Taken from 'The Thrill is Gone', performed by B.B. King.)

posted by chrismear at 3:23 AM on April 11 [14 favorites]

[Aarone]

Cool - please keep this up! I've long been a clueless amateur finger-pickin' acoustic guitar phreak, and getting a little bit of real theory cleared up for me would be very nice! :D

[Celleste]

QQ. I hope you're happy. You're bringing back god aweful music theory lessons from band class. H8 h8 h8!

[jizma]

But music theory is great!

[jizma]

Bump with more stuff, I'll write something that pertains to the game soon, I promise!

[Kahzid]

Hi Jizma

[Gaelaan]

Hehe, Jizma hasn't been around since he posted that.

[jizma]

hehe yeah, maybe I'll flesh this out some more. Have there been any niffty updates to the music system since release?