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Chordian Knot
May 31, 2010 5:35 AM   Subscribe

Help me get my head around chords in music. I think I understand the basics, but then get confused when thinking about progressions, inversions, root movements etc.

This chapter on chords confused me by saying "chord changes have nothing to do with rising or falling pitch.". But if I see the progression I-IV-V-I in C-Major, I assume I would play ( C+E+G / F+A+C / G+B+D / C+E+G ) which seems like a rising and falling in pitch to me. I think this is where inversions make things tricky. It seems like the root of IV can sometimes be lower that the root of I. Is that correct? What about this whole movement by fourths, thirds, etc.

At a more fundamental level, what is the relationship between chords, instruments and the construction of harmony. Let's take a band with a keyboard, bass guitar, and a lead guitar. How do they construct the harmony. Does the keyboard play its own chord progressions independent of the bass or do they work together to create chords and progressions. My gut tells me that the answer is yes and no.

I have a keyboard so explaining things in those terms will help. Basic discussions on triads, major, minor, diminished, augmented stuff is also welcome.
posted by jasondigitized to Media & Arts (12 answers total) 36 users marked this as a favorite
 
All a chord is is a set of notes played together. For example, a basic C chord is c-e-g. Because there is more than one C note, or E note, or G note on a keyboard you can play this chord in different positions. You can play it with the E note on the bottom. You can play it with the G note on the bottom. If you then play an F chord afterward, depending on what positioning you choose, the pitch could rise OR fall.

AS far as a keyboardist and a bassist, the notes they will be playing together will be in the same chord but there's a lot of freedom in WHAT notes each are playing because there are still a lot of actual notes to choose from. Particularly since when doing more complicated chords, more notes are available to choose from.
posted by St. Alia of the Bunnies at 6:13 AM on May 31, 2010


They don't have anything to do with rising/falling pitch because of not only inversion but also because you could simply play them an octave above or below, I think.

All instruments playing together use the same chord progressions. In genres like jazz, "knowing the song" consists of knowing the chord progressions and knowing a few melodies and harmonies that are played within those chords, and then improvising on top of that.
posted by ropeladder at 6:16 AM on May 31, 2010


This chapter on chords confused me by saying "chord changes have nothing to do with rising or falling pitch.". But if I see the progression I-IV-V-I in C-Major, I assume I would play ( C+E+G / F+A+C / G+B+D / C+E+G ) which seems like a rising and falling in pitch to me. I think this is where inversions make things tricky. It seems like the root of IV can sometimes be lower that the root of I. Is that correct?

The book's statement is correct. The root of IV can be lower than the root of I, because you haven't specified what octave each note is in. Is "F" above or below "C"? That question doesn't make sense. If you don't specify the octave, no note is inherently "above" or "below" another note. If you play C on any instrument, and you're then instructed to "play F," you have two main choices: either go up a fourth, or go down a fifth. For instance, if you play middle C on a piano, you can get to F by going up 2 and a half steps, or by going down 3 and a half steps. (On a guitar, you'd either go up 5 frets or go down 7 frets.) Theoretically, you could play an even lower or higher octave of F relative to the C, but a bass player (or left hand of a piano player) is most likely to choose a note within an octave's reach.

Also, you mentioned inversions. Everything I just said assumes the chords are in root position, meaning that the lowest note is the root ("1") note: C in C major, F in F major, etc. But that's not a given. Any note in a chord can be the bass (lowest) note. The composer, arranger, or musicians are free to decide which note is the lowest for any particular chord. For instance, if a band with a guitarist and bassist is playing a C major, the guitarist might play a conventional C major chord with all the notes of the chord C+E+G. Since this guitar chord is presumably going to be higher than whatever the bass plays, it's up to the bassist to decide which note is going to be the lowest note in the chord; the bassist could play C or E or G.

When you combine (1) the point about the bassist (or left hand of the piano) choosing which inversion to play with (2) the fact that even two specific notes (e.g. C to F) could be either rising or falling depending what octave they're in, you can see that the bassist has complete freedom in whether to using a rising or falling sequence given a particular chord progression. And if this is true of the lowest note in the chords, then it's equally true for all the other notes in the chords. In other words, "chord changes have nothing to do with rising or falling pitch."

At a more fundamental level, what is the relationship between chords, instruments and the construction of harmony. Let's take a band with a keyboard, bass guitar, and a lead guitar. How do they construct the harmony. Does the keyboard play its own chord progressions independent of the bass or do they work together to create chords and progressions. My gut tells me that the answer is yes and no.

In general, all the instruments play a single chord together. This is usually going to be something simple like "C major" or "G major." Even if they seem to be playing chords/notes that are "independent" of each other, you could still look at them as playing a chord. For instance, if the bass is playing an A note, and the guitarist is playing a C major (C+E+G), are they playing "independently" because they're not playing any of the same notes? Well, you could say that. But it would be more useful to say that they're playing A minor 7th (A+C+E+G). If there's also a keyboard playing E minor (E+G+B) at the same time, you could say the whole band is playing A minor 9th (A+C+E+G+B).

What would constitute the instruments playing "independently"? Well, if the bassist played an A and the guitarist played a C major (as in the above examples), but the keyboardist played, say, an F major (F+A+C), I'd say the keyboardist is playing independently of the other two. But here's the thing: that wouldn't sound very good. You can try it if you have a keyboard.

The counterexample would be "polytonality," which means music that's in multiple keys at once -- but that is way outside the norm for any kind of popular music. As you can see from the Wikipedia entry, you can hear this in certain compositions of Stravinsky and Charles Ives. As Wikipedia says, if you want to hear two chords at once, get Stravinsky's "Petrushka" and listen to the very beginning. I believe this is the most famous example. The fact that there's one outstanding example of this device in all of music history shows how rare it is. Listening to "Petrushka" is a wonderful experience that I highly recommend, but it's not too relevant to any kind of popular genre of music that I'm aware of.
posted by Jaltcoh at 6:24 AM on May 31, 2010 [5 favorites]


I think my confusion comes because I am thinking in terms of melodic intervals. To me, saying I-V means 1-5, or moving up the scale. But what I think I am hearing is that I, V, or ii simply represents the keys to be played and has nothing to do with the order / octave of those keys. So V in C Major is not always C+E+G. It could also be E+C+G, or G+E+C, etc.
posted by jasondigitized at 6:38 AM on May 31, 2010


One thing that may be confusing when studying theory and trying to compare it with what actually happens in music is that theory is to music what grammar is to language, especially spoken language - the rules are broken left and right and to some extent suffer from having been written after the fact, i.e. have been developed to explain and provide vocabulary for what musicians were/are already doing.

That doesn't mean they're not valuable- in fact they're very valuable in providing those examples. But it's easy to get confused, especially if you're a beginning theory student, by what you see actually happening.

One thing that confused me about chords, so I'll mention it - yes, all instruments in an ensemble are playing the same chord at any given time (except in the rare case of polytonality, as mentioned by jaltcoh), but if that's the case, how can the solo player be playing around on all these different notes? If the chord is C-E-G, how can the solo/melody, and even other instruments playing counter-melodies, be playing other notes?

The answers to that will be explained (somewhat) as you progress through theory, but the short answer is - they manage. But in 99% of the music you'll actually hear, everyone is still said to be playing within the same chord.
posted by randomkeystrike at 6:40 AM on May 31, 2010


"confused me by saying "chord changes have nothing to do with rising or falling pitch.". But if I see the progression I-IV-V-I in C-Major, I assume I would play ( C+E+G / F+A+C / G+B+D / C+E+G ) which seems like a rising and falling in pitch to me."

Not necessarily. Your example assumes you would play each chord in first position and in the same octave. However, you could (for example) play ([middle] C+E+G/ A [below middle C]+C+F / G[below the A you just played]+B+D / G [same G)]+C+E ) . That would make the same progression fall and rise in pitch, rather than rise and fall.

" It seems like the root of IV can sometimes be lower that the root of I. Is that correct?" - Absolutely. In fact, on a piano you could play the chords I - ii - iii - IV - V - vi - vii in a given key going down the keyboard on each chord. I'm not sure why you want to, but it's certainly possible.

"Let's take a band with a keyboard, bass guitar, and a lead guitar. How do they construct the harmony. Does the keyboard play its own chord progressions independent of the bass or do they work together to create chords and progressions. My gut tells me that the answer is yes and no. "

Your gut is wrong. The answers are no and yes. All the instruments should be working together to create chords and progressions. Otherwise it's going to sound pretty ugly.

The ways that the instruments can work together are many, and can vary from simple to complex. I'll give you some simple options for the combo you use in your example:

Keyboard - can play complete chords, using different rhythms and inversions as required by the song to keep things interesting. Maybe the keyboardist will also throw in some filler licks or even a melodic break based on the current chord progression.

Bass - at the simplest level, the bass player might play just the root note of whatever chord the keyboard is playing, or possibly alternate between the root and fifth of the chord. At a slightly more complex level, the bass might play a root and fifth, but play a connecting line that "walks" from one chord to the next when the keyboard is getting ready to switch chords. At a still more complex level, the bass player might play a jazzy walking bass line, where beats 1 and 3 are chord tones of the current chord, while beats 2 and 4 are connecting tones which may or may not fall in the current chord.

Lead guitar - will usually be playing melodic lines (as opposed to rhythm guitar, which would usually be playing the same chords as the keyboard). Those melodic lines might be built on a scale in the key that the keyboard is playing in. They might be built on what I would consider a "complimentary" scale (not the official music theory term). For example, if a rock band is playing in the key of A major, the lead guitarist might construct his solo around an A minor pentatonic scale. The tension between those minor melodic notes and the major harmony is part of what give rock its distinctive flavor. Alternately, the lead guitarist might construct his riffs around whichever chord the keyboard is currently playing. Listen to Day Tripper by the Beatles. The signature riff starts on an E, while the rhythm guitar plays an E chord. When the rhythm guitar switches to playing an A chord, the lead guitar continues playing the same exact signature riff, only now starting on an A note.

There are a lot more possibilities than these, but you can grok all of what I've laid out above, it should make everything more comprehensible.
posted by tdismukes at 6:43 AM on May 31, 2010 [1 favorite]


If you kept every chord in root position (Do-Mi-So) and moved through them in parallel, you would have a contour that rises and falls. It also sounds a bit monotonous, like a guitar player sliding up and down the neck playing bar chords.

Inverted chords (Mi-So-Do, So-Mi-Do) can be seen as tools of efficiency when you think about individual voice leading for each note in a chord. When you have a note in a chord (C in C major, for example), and you change to another chord (G, for example), that C wants to move as little as possible. Instead of moving up a fifth to G, your ear wants that C to move stepwise to the nearest note in the G chord. This could be B or D. The same thing goes for the E and G of the C chord.

The best way to understand how this works is to study Bach four-part chorale music, where each voice moves in stepwise motion, with a smooth melodic contour, and all four voices in combination create harmony that evokes chord changes.

In a rock band, the instruments combine to create harmony, albeit without many of the strict rules that create the logic of Bach's music. So you get a lot of doubled voices, parallel fifths, movement in the same direction (bar chords on a guitar), and even some new, unintended harmonies. This last phenomenon can perhaps best be illustrated by the bass line that P. Diddy combined with the sample of Diana Ross's "I'm Coming Out" for Notorious B.I.G.'s "Mo Money Mo Problems." The original song is roughly in a major key, and Diddy adds a bassline that emphasizes the relative minor key.
posted by billtron at 6:52 AM on May 31, 2010 [1 favorite]


I think my confusion comes because I am thinking in terms of melodic intervals. To me, saying I-V means 1-5, or moving up the scale.

Yeah, a chord progression is completely different from melodic intervals. if you're told to play "C major, G major" (I-V), think about all the different ways you could do this. You could play C+E+G, starting on middle C, and then move the whole thing up so it starts on the G above middle C. But you could, instead, move the whole thing to the G below middle C. But you might think either of these choices sounds too clunky, so you decide instead to move C down to B, move E down to D, and keep the G where it is. This would be playing a "1st inversion" of G (i.e. the 3 of the chord, or B, is the lowest note). You could say this is a more elegant "voicing" than either of the first two examples where you just pick up your hand and plunk it down in the same position (i.e. a major triad in root position) starting at the root of the next chord (G). Another option would be D+G+B, which would be a "2nd inversion," meaning the lowest note is the 5 of the chord (D in G major).

Basically, you need to be aware of voicing, or voice leading. It's a huge dimension of music that's easy to overlook.
posted by Jaltcoh at 6:56 AM on May 31, 2010


I think my confusion comes because I am thinking in terms of melodic intervals. To me, saying I-V means 1-5, or moving up the scale.

The important thing to understand is that even if you are talking about melodic intervals, 1-5 doesn't necessarily mean moving up the scale. Scales repeat indefinitely -- after the 7th note you get back to the first. So 1-5, or C-G, can always mean going up or going down.

Also, as far as nomenclature goes, Roman numerals are generally used to refer to chords while arabic numerals refer to individual notes. So I-V is a chord progression while 1-5 is a melodic progression.

So V in C Major is not always C+E+G. It could also be E+C+G, or G+E+C, etc.

V in C major is a G chord, G B D, but yeah, you get the idea.

Also, if you're wondering about what randomkeystrike mentioned:

One thing that confused me about chords, so I'll mention it - yes, all instruments in an ensemble are playing the same chord at any given time (except in the rare case of polytonality, as mentioned by jaltcoh), but if that's the case, how can the solo player be playing around on all these different notes?

You can find a brief explanation of how solos fit over chord progressions here.
posted by ludwig_van at 7:20 AM on May 31, 2010


"One thing that confused me about chords, so I'll mention it - yes, all instruments in an ensemble are playing the same chord at any given time (except in the rare case of polytonality, as mentioned by jaltcoh), but if that's the case, how can the solo player be playing around on all these different notes? If the chord is C-E-G, how can the solo/melody, and even other instruments playing counter-melodies, be playing other notes?"

To build somewhat on the explanation ludwig_van links to ...

At a first approximation, it's often useful to think of the melody (whether a vocal line or a guitar solo) separately from the chord progression. If you're playing your I-IV-V-I progression, for example, it's highly unlikely that a good melody line would consist of nothing but tones from the current chord. Instead, you can think of the chord progression as a substrate that underlies and gives context to the melody. As mentioned in ludwig_van's link, the melody can build tension by moving away from the chord tones and resolve it by returning to a chord tone. (It gets more complex than that, but this provides a good starting perspective.)
posted by tdismukes at 7:51 AM on May 31, 2010


And not only will melodies stray away from the chord, it's also quite common for the melody or lead to stay on a note while the chord changes around it. So, not only does a chord progression have nothing to do with rising or falling pitch, it doesn't necessarily even mean changing pitch (at least as far as the melody goes) at all.
posted by eafarris at 8:33 AM on May 31, 2010 [1 favorite]


Historically, one of the preferred ways to match a bass line to an existing melody was in any case contrary motion. (The background of this is counterpoint rules, and specifically the requirement to avoid parallels in fifths or octaves, in combination with specific rules of how to prepare and resolve dissonances) No matter whether certain modern chord practices are much more liberal than that, the idea of things moving apart and coming together lingers strongly on. The rest of the chord is in any case between the two and will move up or down according to its own mechanisms as eafarris says.

And yes, a given bass line and a given melody implies that only a certain selection of possible chords is possible, or you'll stray away from one single tonality and create a mush (conversely, in some patterns, a pre-determined sequence of chords serves the player - or the composer - as a guide and inspiration for making the melody). This means that at some stage, the musicians will have to agree about the chords; naturally there are codified ways to do this. In Baroque music, composers put (or were supposed to put) a set of shorthand figures above the composed bass line that identify the chords. It is the player's task to decide upon where to place the chord on the keyboard and to perhaps improvise some runs or embellishments within that harmony, but the basic harmony was thus prescribed, especially in difficult spots. If the figures are missing in such music, you can make up your own figures by looking at the combined bass and melody of the piece and deduct the appropriate harmony. If several instruments play the chords together (say two lutes, a harpsichord and an organ), the players normally compare their figures so there are no discrepancies. Sometimes there's no time for this. That's where the fun really starts...
posted by Namlit at 9:54 AM on May 31, 2010 [1 favorite]


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