Okay, here goes. Music theory is basically the study of all the different aspects of what makes music, music, and how people put those things together to form songs (how's that for a circular definition?). There doesn't seem to be any agreement on any common characteristics that music shares universally -- for example, some forms of non-Western music don't have a sense of rhythm in the sense that it lacks a basic beat, or "pulse," which is more or less a basic building block of most Western music. But it's more or less agreed that music has some or all of these traits:
- rhythm
- melody
- harmony
- structure
- timbre
- dynamics
...at least in the Western world. The less Anglo-centric categorization of musical aspects has four main traits:
- pitch (the frequency of a sound, or how high or low it is. Includes melody, harmony, tonality, tessitura, and tuning)
- timbre (this basically means the quality of a sound and includes words like fundamental, spectra, envelope, overtones, voices, tone color, articulation. I have no idea what most of this means)
- intensity (dynamics and stress. At least this one was easy)
- duration (anything having to do with the temporal traits of music, as John Cage would say. Includes pulse, beat, rhythm, rhythmic density, tempo, and meter)
- structure (includes motive, phrase, period, section, exposition, repetition, variation, development)
- texture (the interaction of temporal and pitch elements, include homophony, polyphony, heterophony, and simultaneity)
Pitch
You'd think pitch would be fairly universal musical characteristic -- after all, all sounds have a frequency, right? Well...sort of. Actually, they have more than one frequency, and that all has to do with timbre and a lot of other things.
Pitch is definitely one of the three characteristics of any sound in general (the other two being intensity and timbre). It is basically how people map the tone of a sound they hear to a position on the musical scale, and it's based on the frequency, in Hz (and also, at really high or low Hz, on sound pressure, but I don't really care at this point). If you remember your physics, you will recall that frequency and wavelength are inverses of each other, so higher frequency (higher notes) means shorter wavelengths.
Some people have "perfect pitch," which means that they map tones really accurately (if you played a G on a guitar and assuming it was tuned in the "standard" way, they would recognize the note as a G) -- however, all heard or "perceived" pitch is more or less relative, because unless you're actually measuring the Hz of a sound, there are ways to throw off your innate perception of pitch. In particular, the overtones (more about this later, because it kind of deserves its own section, as it is really pretty interesting) of a sound may screw with the perception of pitch, however, in the case of well-made instruments and in most "normal" cases, perceived pitch is more or less pretty close to the "real" note.
There are exceptions; a famous example is the Shepard scale, which is basically a series of octaves that go up the scale but never seem to go higher, as a whole. There is a video of it here:
Most instruments that you think of as playing actual notes on a scale are said to have "definite pitch" (it also means they have "harmonic spectra", but we're going to cover that later in the overtones section). Things like percussion instruments don't have an easily discernible pitch, so they have "indefinite pitch." However, a sound with indefinite pitch can still sound higher or lower than other indefinite pitched sounds (the different drums in a drum set, for example), and that has to do with being comprised of higher frequencies.
The difference between two pitches is known as an "interval." An "octave" is an interval that corresponds to either doubling or halving the frequency. More about this in the scales part.
Historically the standard tuning of notes has changed a lot over time, but it has a lot to do with the physical medium and the physics of vibrations and tends to be not very interesting. Bach did a lot of work on this subject (see "The Well-Tempered Clavier)...etc, etc. Right now, the A above middle C is tuned to 440 Hz, and that's really all I care to say on the subject.
Scales and Modes
Here's the Circle of Fifths stuff. A scale is just a sequence of notes in ascending order (ascending meaning the frequency gets higher in some predictable way). There are a lot of different types of scales and we'll talk about three: chromatic, diatonic, and pentatonic. In Western music, a 12-note scale makes up one octave. It's called the "chromatic scale" and each note goes up by one "half-step," or "semi-tone." The "tones" or "whole steps" are made of two half-steps (funny how that works). For example ... going from C to D takes two half steps -- C to C# and C# to D. Oh screw it -- here's a video.
Don't worry about the fingering, or anything after 0:45 seconds. It's just nice to see it on the piano because it's all laid out in front of you. If you're starting at C, a semi-tone or half-step is to the black key to the right of C (the C#/Db), another semi-tone takes you to D, and etc etc.
In the piano world, everything sort of revolves around middle C -- it's in the middle of the keyboard and you can play a C major scale without any black keys (on the piano, black keys represent sharps and flats). In other instruments, basing everything around C doesn't make as much sense. But it's what I use here because it's simple.
Anyway, the diatonic scale is the "7-tone scale." The major diatonic scale is the basic happy sounding scale and there are three minor scales: the harmonic, the natural, and the melodic, which are basically all different sad paths. The natural minor, if you write it out in a series of half and whole steps, looks exactly like the major scale with a different starting point. For example, if you start at C and play only white notes (no sharps or flats), you will play a C-major scale. If you start at A and play only white notes, you will play a natural A-minor (incidentally, moving from C down to A takes 3 half steps. To play a minor scale with the same number of sharps/flats as any major scale, go to the first note of the major scale and go down by 3 half steps. That's all in the Circle of Fifths). The harmonic minor has an augmented 7th note (the 7th note in the scale is sharp) -- it's found quite often in Arabic music. There are actually two melodic minors depending on whether you go up or down, and it's more complicated than I care to get into.
Here is a video on the minor scales, optimistically called "How to Play Piano." At about 3 minutes in he finally gets down to business, but then it's pretty good, and he explains the minors in terms of how they sound with the 7th note (the "leading seventh") which is supposed to sort of lead into the tone (the bottom note of the scale, but one octave higher) where you end, and a little bit of history surrounding the melodic minor, which is interesting if you happen to like that sort of thing:
The other really important scale is the pentatonic (5-note) scale, which is the basis of a huge amount of blues and hence, a lot of rock music. The very blatantly obvious example is the intro to the song "My Girl" by The Temptations.
If you built a song on the C-major scale (and that means C, the note the scale starts on, is your "tonic" or "tone" and has to do with harmonics and a bunch of stuff we'll discuss later), you say it's in the Key of C-major. Usually no one cares in the context of rock music what key you're in, but there are ways to determine what key any song is written in, along with if there are any modulations or key changes in the course of the song. What note something ends on (and to a lesser extend, the key it starts on) is generally a pretty good indication of the key. Also, sometimes the "dominant" or 5th note in a scale will tell the key, as it tends to be very prominent. Basically, if you want to figure out how to change the key of a song, you use the Circle of Fifths because it shows the relationships between all the notes on a chromatic scale and how by changing the key you're adding sharps or flats to your scale, etc. Here is a picture of the damn thing:
But instead of being in a key, you can also be in a mode. A "mode" is kind of confusing. Basically, if you take a C-major scale but instead of basing the song on the C note, you base it on a different note in the scale, only you still use the notes of the C scale, you're in a mode. There are a bunch of different names for different modes depending on which note from the tonic (bottom note of the scale) you start on (starting on the second note is called a Dorian mode, and so forth).
I'm not really sure, but I think the Radiohead song No Surprises is an example of an A modal Phrygian. That intro is using the notes of the F major scale but it's transposed to A.
Melody
So, having said all that, it's a lot easier to talk about melody (also called line or voice) now, because melodies are composed on the basis of scales and modes. Melodies are used in all sorts of ways: point and counterpoint (multiple melodic lines played at the same time -- again, Bach is the person to look at here, as he kind of wrote the manual on how to do counterpoint properly), verse-chorus (usually two different melodies around which sections are constructed), etc.
Melodies are generally built around several motifs, which are basically small musical ideas that are repeated and retain some kind of compositional importance -- they're easily recognized, the rest of the piece builds on them, or they represent a person or idea (a lietmotif). Basically, they're just a smaller unit of a musical phrase that is in itself a complete and well-formed idea.
I mention all this because a "riff" is a kind of motif that is a repeated musical phrase that forms the rhythmic basis of the composition -- like the riff of Ravel's Bolero or the intro to Black Sabbath's "Iron Man." The main thing about a riff is the rhythmic aspect -- and if it is a memorable enough rhythm, it can also be a hook. A "hook" is basically a catchy motif (although a hook doesn't have to be melodic, it can also be rhythmic), usually in the chorus, and melody in general is huge in all forms of pop music. Obligatory Youtube links to follow:
I think this song pretty well illustrates both concepts. The main theme/motif is actually in the keyboard section in the beginning, and then she goes into a bridge, and then in the chorus ("Keep me closer/I'm a lazy dancer/When you move I move with you"), you have that nice synth-pop hook, which echoes the musical ideas of the main motif (the descending line). Also, it's a good song.
Metric - Collect Call
Harmony
So you have a melody, which is one pitch based on a tone (bottom note in the scale). Once you start adding in other pitches at the same time, you form chords. That is the basis of harmony, the "vertical" aspect of song structure (if you consider melody to be the "horizontal").
In Western music, the chord is usually based on the interval of thirds, for example, a C major chord is CEG, where CE is a major third, and EG is a major third. This CEG thing is an example of a "major triad." Why does this sound good? Because apparently the three tones have frequencies in a nice harmonious 4:5:6 ratio.
Anyway, chords are important because they influence how "relaxed" or "tense" a piece is. Certain chords sound relaxed (like that major triad) and other chords give tension to the piece, which can be "built up" (led into by a succession of relaxed chords) and then "resolved" by going back into relaxed chords, thereby creating a sense of forward movement and catharsis in the music, giving it kind of a structural storyline and making it more interesting. In technical terms, the names for this relaxed and tense is "consonance" and "dissonance."
Hmm, what can I link for an example of complex harmony? How about some Pink Floyd?
Tessitura
This is an Italian term which refers to the range for a singer or a musical instrument. It's not terribly pertinent to rock music, but it becomes kind of interesting when you get people like Mariah Carey who has apparently a seven octave range.
Tonality
Tone/tonic -- we already went over this. The tonic is the bottom note in a scale, which controls which key something is in.
Timbre
At the most basic level, timbre refers to the "color" of a sound -- how the physical details of what the sound comes from imparts certain characteristics that allows you to distinguish between the sound a saxophone makes and the sound a guitar makes, for instance. And it depends on a whole bunch of fairly technical things you probably never thought about.
The five attributes of timbre are:
- difference between tones and noise
- spectral envelope
- time envelope
- changes in spectral envelope and fundamental frequency
- a sound's prefix
The first one seems fairly obvious at least. Although it probably warrants mentioning that music in general makes use of "noise" in fairly inventive ways, including making them be integral parts of certain pieces. I think you all could come up with an example of music that you personally consider to be noise. Although that's not really the same thing, is it.
Spectral Envelope and Overtones
Remember when I said that a sound doesn't just consist of a single pitch? When you play middle A on an instrument, you're not just producing a frequency of 440 Hz -- you're actually producing an entire range of frequencies, most of which you can't hear distinctly (and all those other frequencies make up the overtones). The pitch is usually determined by the lowest frequency, which is called the fundamental frequency. Harmonics are the frequencies that are produced that are integer multiples of the fundamental frequency, and partials are the non-integer frequencies. Most instruments that have definite pitches produces harmonics, and the other ones produce both partials and harmonics.
The different overtones usually decay at different speeds, so as the sound lasts longer, it is possible distinguish all these different frequencies in a single note (assuming you've been trained to hear them). That leads into a discussion of why sounds may sound different when played staccato or legato and all that sort of thing. For now, here's a video that pretty well demonstrates this whole business:
Cool, huh?
Time envelope
The timbre of a sound also depends on four variables called the ADSR - Attack, Decay, Sustain, Release, that together determine a sound's "loudness" over time. Basically, if you ever wondered at a really fine-grained physical level what distinguishes a loud note played on the piano from a soft note -- it's how fast you strike the key. Your finger knows this inherently, but it's not immediately obvious to the mind. ADSR is that concept, applied to all instruments.
Pretty basic stuff: attack is how quickly the sound reaches full volume after you initiate it. Decay is how quickly it reaches the sustain volume. Sustain is, of course, the constant volume the sound attains until you stop playing the note, and release is how quickly the sound fades away when you stop playing it.
Different instruments all have different ADSR envelopes, which is one of the ways you can tell different instruments from each other. Their "loudness over time" variable is one way in which different instruments' sounds are unique. For example, a plucked string note has a different ADSR than an organ note (plucked string notes are loudest at the instant closest to when you plucked them and then they fade away slowly, organ notes are mostly at constant volume until you take your hand off the key, and then they fade away very quickly). On a synthesizer, these variables are all configurable; that's how you make a synthesizer sound like certain instruments. Woodwind instruments and other instruments that you blow into also allow you to vary the loudness in the middle of a note, and that's another thing synthesizers allow you to control, sometimes.
I'm not going to discuss the other things in that list, because it seems to me that spectra and ADSR are the two most important timbre elements (and also, the most interesting).
Intensity and Stress
This refers to the volume of sounds, but as we already know, that leads into also how you articulate notes (staccato vs legato) and also how fast you play things. There's a lot of technical Italian names for all the relative volumes. Forte -- loud. Piano -- soft. Crescendo -- getting louder. Decrescendo -- getting softer.
Fun fact: the piano was originally called the "fortepiano" because the harpsichord, the older version of the piano, didn't allow you to play with any changes in volume. The interior mechanism actually plucked the strings instead of using a hammer to hit the strings, so you only got one loudness. The piano was therefore a big technological step up.
I only mention this because a lot of musicians today seem to forget that they are allowed to work with the entire spectrum of volume and not just, you know, a single volume set to "generically loud". Just saying. Also, having your producer fade the song out at the end does not count. In fact, I hate fading out. It's such a lazy way to end your song. /endrant
Pulse
Pulse is the basic beat of a song, which doesn't have to be explicit, but it's definitely there, and it definitely repeats (for an example of a song that doesn't have an explicit beat but still has a pulse, see Imogen Heap's "Hide and Seek"). The tempo of a song is the tempo of the pulse. There is a natural tendency to group pulses into groups, such as strong-weak -- and if you have a pulse group that is distinct and repeats a lot, that's called a "meter." Like in poetry.
Beat
Beat is somewhat interchangeable with pulse but can also be applied in a wider sense to the basic unit of time in a song and also includes things like the speed of the song. It is usually divided into measures, which are indicated by the time signature, such as 4/4 time (4 beats to a measure, quarter note is one beat), 3/4 time (waltz time, three beats to a measure, quarter note is the one beat), etc. Some other definitions: "downbeat" is the impulse at the start of the bar. "Upbeat" is the something that leads into the downbeat.
Normally, our ear groups a series of beats into strong/weak pulses, no matter if they are actually stressed that way or not. In a measure of 4 beats, we tend to hear the first and third beats as stronger and the second and fourth as weaker. Those are called "onbeats" and "offbeats." If you frequently accent the offbeats or really anyplace where you wouldn't normally expect the stress, you use a lot of "syncopation." For example, in reggae music it is customary to stress the 2nd and 4th beats.
A "backbeat" is basically the accenting of the offbeat, which is usually done by the snare drum.
I guess everyone is familiar with what "rhythm" is. Wikipedia has a section on why human beings evolved to "appreciate" rhythm:
"In his series How Music Works, Howard Goodall presents theories that rhythm recalls how we walk and the heartbeat we heard in the womb. More likely is that a simple pulse or di-dah beat recalls the footsteps of another person. Our sympathetic urge to dance is designed to boost our energy levels in order to cope with someone, or some animal chasing us – a fight or flight response. From a less darwinist perspective, perceiving rhythm is the ability to master the otherwise invisible dimension, time. Rhythm is possibly also rooted in courtship ritual.[1] Neurologist Oliver Sacks posits that human affinity for rhythm is fundamental, so much that a person's sense of rhythm cannot be lost in the way that music and language can (e.g. by stroke). In addition, he states that chimpanzees and other animals show no similar appreciation for rhythm."
Western music has fairly simple rhythms in comparison with the rest of the world. Most of our music is grouped into measures that are divisible by 3 or 4 (really, also 2, but a measure of 2 is kind of awkward to work with). If it's divisible by 3, it's complex, if by 4 (or 2) it is simple. But African music makes use of a lot of "poly-rhythms," which are two or more rhythms playing at once (like a triplet played against a series of two), and lots of other types of music use more complex measure structure like 7 or 13.
Structure
The most basic units of structure are the beat and the motif, and above that, the phrase (which is just a higher level of organization of the two preceding things, whereby if you break it down any further, it looses its uniqueness). The main things to note when talking about structure are repetition and variation -- those are the bases upon which structure is composed.
Timbre
We've already been over this.
Dynamics
Not rocket science, except that apparently some musicians forget that other dynamics exist aside from "fucking loud." Not that I have anything against fucking loud, there's just...you know...all the other variances in volume in the world to play with, and hardly anyone does. Just saying.
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