*N.B. I assume the reader knows a bit of theory*
*N.B. This article deals with modern rock, not classic rock, and only with more mainstream genres, not including artrock postrock or progressive. But due to lack of examples in pop music, most egs are from slightly more obscure bands*
Also, it's only my second ever article on UG :) So be nice k ^^
The article you're about to read, is very texty, due to the fact that examples are rather hard to find, and hard to hear too even if found (since the parts of the chords are probably distributed among the parts)
First we start with altered chords, which are simpler to explain rly :) Altered chords are essentially chords with add-on notes not in the basic triad. For eg, your V7. While V7 is a rather popular chord, with a history tt stretches all the way into the dawn of classical music, altered chords of say chord IV are less commonly used, but (to me) can sound much nicer than your oldschool V7.
A 7 chord is essentially a basic triad, with a added 3rd on top of the highest note (this forms a 7th from the new top note and the bass note, thus the name). For example, while a normal C major chord is C-E-G, a C7 chord will be C-E-G-B. A 9th chord adds yet another 3rd, 11th another, all the way up to 13th, at which point adding another third brings you back to the tonic note.
Of course, the more note you add, the more it detracts from the original chord, and makes the chord weaker. However, it does add a rather new and vibrant color to the chord, that makes it rather special.
When writing a song, I don't really advise you to use these chords in the guitar part itself, unless its an acoustic guitar. If an electric guitar were to play a chord like that, it would sound very distorted, because of the 7th and the 9th, even in the case of a powerchord, eg.
it sounds rather grindy, doesn't it! Even if you were to write for acoustic, I would advise against raising the number too high, since like I said adding more and more notes on top tends to make the chord weaker and weaker. So my advise would be to put the added note into the melody, or a riff, while the guitar chord stays the normal powerchord. I will now try to explain the sound, of the different possible 7ths and 9ths chords. When you try to hear the sounds of the chords, I advise using a piano, which doesn't distort like an electric guitar, but brings out the overtones rather well :)
Btw I give examples in C major for simplicity.
I7 - It makes the I a lot less strong, and has a general very suspending kind of feel (like an unresolved suspension). Therefore I do not really advise using this one, since most of the time I has to be a rly strong chord.
I9 - Same problem as above. Except worse.
ii7 - This is a really good chord to use, with a history almost as long as V7. It adds vibrancy and a rich tone to the chord, without making it much weaker. Chord ii is normally meant to be weak anyway. So eg. putting Cs in the vocals part of the guitar riff is perfectly acceptable over a D minor chord.
ii9 - This is stretching it a bit, but it's still possible :)
iii7 - Chord iii isn't used very often, but iii7 is a worthy alternative of iii. While it will not sound as natural as ii7, again its perfectly acceptable to have a D note in your riff or melody over an E minor chord.
iii9 - Not recommended. Stretches it too far.
IV7 - Now this is one of my fav chords. Having an E in your riff or vocals over an F major chord gives it a very magical feeling. Bring a IV9 in is even better than having a IV7. Just try having a G in your vocals over a F major chord. Gives this hollow, magical feeling best described as flying, and theres this empty space between you and the ground. (forgive the melodrama)
V7 - old school. wont elaborate on this. it's a ready substitution for V anytime.
V9 - Now this is a very interesting chord, except not in this state. I like to write Vb9. That is having an A flat over a G major chord. Oh and throw in the F too. This gives it a veryvery borrowed chord feeling (refer to section on borrowed chords), of nostalgia nostalgia nostalgia. If you wanna be badass, you can add a C to the mix to give an 11th, but thats a bit stretching it so ill recommend resolving the C to a B. (as a suspension). If you want, you can even add an E, giving a 13th chord, but again I'd recommend using the E as a suspension, resolving to a D.
vi7 - This is a good one to use. G over A minor chord. Sort of like IV7, gives a flying effect, though a lot less powerful id say.
vi9 - Stretching it a bit, but possible :) experiment around!
I won't cover on chord vii, since its a diminished chord. So yup, that sums up the section on altered chords :) I have tried to describe the feeling of the chords, once again, but dunnoe how well I've done it >.< Just experiment around and u shld be able to get your own sense of whats going on :D
For an example, try Saosin's Seven Years. In solfege, the guitar parts during the verse goes la-do-so-do-la-do, fa-do-so-do-fa-so. The first part would be a vi7, while the second part is a IV9. Note the shared do and so notes :) Using these shared notes will make your chords appear much more natural, cos they act somewhat as pedal points, or rather pivots to hinge your chords upon.
These two chords are something that you've probably encountered, say, while doing your music theory. Diminished chords consist of two minor thirds stacked on top of each other, while augmented have two major thirds. (Rmb that major chords have a minor third on top of a major third, while minor chords have a major third on top of a minor third). Eg.
C major - C-E-G
C minor - C-E flat-G
C diminished - C-E flat-F sharp
C augmented - C-E-G sharp
Diminished and augmented chords are not easy to use in rock music, because the weird intervals sound rather dissonant, esp diminished chords (note that tritone between the tonic and the lowered dominant. its called a devil's interval because of its dissonant quality). In classical music, they are used because they are eventually resolved by a consonant chord, but the difficulty in rock music is that even the slightest bit of dissonance will cause nasty clashes, esp in those griding electric guitar chords. There are however several ways to work around this.
Firstly, you can use power chords. This will prevent your chords from being too distorted. While
is a normal chord,
would be a diminished chord, and
would be an augmented chord.
(If the fingering is odd, try it in dropped D tuning. That should make it easier to play.)
Now, we can finally move on to how to use these chords. Like I said, diminished and augmented chords aren't easier to use at all, and the ones listed are about the only ones I've learnt how to use on a regular basis. Of course, there are always more that you can experiment around with, but do be careful with them!
ii diminished - This is an awesome sounding chord, that is in fact a borrowed chord (refer to section below). You can use this very easily, leading to a chord V and then a chord I as a perfect cadence. You can also insert a chord iv (borrowed) between ii diminished and V. It is also my advice to try out adding the tonic note into this to create a D-F-A flat-C (in C major).
In fact, that is the only diminished chord I use regularly. Other diminished chords are possible as transitory chords before changing to another chord, such as adding a #iv diminished in between a Vb/V (refer secondary dominant) and a chord IV, in a chromatically descending bass progression (refer bottom section).
bVI augmented - This is the only augmented chord that I use regularly. Comprising an A flat-C-E in C major, this chord is one awesome chord that can be used as a substitute for chord iii in some situations. For more details, refer to borrowed chords section.
Again, you can use augmented chords are brief transitory chords, but generally the bVI augmented as the best example of a nice-sounding augmented chord.
Finally, we get to borrowed chords. As you might have noticed, I have put a plenty lot of 'Refer to section on borrowed chords'. A borrowed chord is essentially a chord that is 'borrowed' from the other side. Ok sounds extremely vague. What I mean is, say in a major key, a chord that can be foudn in the parallel minor would be a borrowed chord, and vice versa. For example, instead of having a F major chord in C major, I can use an F minor, which is a chord iv (note small letters denoting minor chord, instead of the normal capital letters for chord IV).
A flattened sixth note is the most common alteration used to give borrowed chords the "borrowed-chords" sound. Anything with a flattened sixth, normally tends to sound extremely nostalgic :) and its by far my favourite note. I can give lots of examples on how to use this:
ii diminished. I've already explained this one! You can use this simply in progressions such as iidim-V-I (perfect cadence) or iidim-iv(borrowed)-V-I. Note again that because iidim and iv borrowed share a lot of notes, these two chords are often interchangeable.
chord III: instead of a normal chord iii, i put chord III. This is because I can use this a flat to create a chord E-A flat(G sharp)-B. I know that harmonically or theoretically speaking a G sharp would be the one to make this a major chord, but when I hear this chord, it sounds a lot like borrowed chord (A-flat). This chord sounds very much like a modulation to the minor, and leads very strictly to chord IV. Eg. IV-V-iii-vi-ii-III (which will return to chord IV)
chord iv: this is by far the most common. You see it overuse in almost every single sad movie soundtrack I know. You can use this any time in place of a normal chord IV. Be careful that if you use powerchords, you will have to use your A flat elsewhere, perhaps in your melody or guitar riff, or maybe even your violin/keyboards part. Eg. I-iv-vi-V or a simple I-iv-I-iv. An example I can show you is from the Main Title piece of The Notebook OST, the very second chord used in the piece (it does return later, but I'm too lazy to pick them out), in 0.07-0.11 in this video. It uses a I-ivc, with the tonic as the bass to provide a tonic pedal.
chord Vb9. Refer above to altered chords section. Use it in place of a V anytime. This is a very chord, though, like I said, and you shouldn't use it if you already have a chord iv somewhere, otherwise you might overdo the flattened sixth thing :P
bvi augmented. I've also explained this one at the augmented section. A common progression in Jap music would be vi-bvi aug-V-Vb/V (refer to secondary dominant section)-IV. And yet another way you can use this chord would be IV-V-bvi aug-vi (as a stand-in for chord iii in the normal progression IV-V-iii-vi). I've also tried using them in ways such as I-bvi aug-vi-IV, but I haven't heard this progression elsewhere. A Western example I can think of offhand is The Rise Of Science's Teenage Martyr, which uses this chord in its chord progression right at the beginning of the song, from 0.05-0.08 in this song. Progression there is vi-bvi aug-I-V. Note the slightly different progression, cos this is from an indie band.
That sums up the flattened sixth section :) A last borrowed chord that can possibly be used is the bVII chord (B flat-D-F in C major), which is the flattened seventh. Used in a descending bass sequence such as I-bVII-vi-IV, it replaces the normal Vb, and gives a more weird feeling that I can't really describe. An example would be Boys Like Girls' song Holiday, from 4.37-4.40 in this video, during the piano coda. (chord progression is I-bVII-vi-IV)
Oh btw, it is possible to slip in a flattened sixth in the flattened seventh chord, but that is a bit on the dissonant edge, but do experiment around and try it out :)
This is a rather specific chord, but it sounds great in a progression. A secondary dominant is essentially the dominant of a diatonic chord, that isn't a diatonic chord in itself. What I mean is, say in the key of C major, G major is the dominant of C major. The dominant of G major would be D major. But rmb that chord ii should be minor in C major, so D major is not diatonically related to C major, but it can be used as a secondary dominant, in this case of the dominant. Other secondary dominants of chord iii (B major) or in fact any other chord is used in classical music, but rather hard to use in rock music. A secondary dominant is denoted V/X, with X representing the whatever chord that the chord is a dominant of.
It is easiest to use a V/V (secondary dominant of the dominant) in its first inversion, having your bass on F sharp (F sharp-A-D in C major), because of the fact that the secondary dominant always leads to either a chord IV, or a chord V. Possible progressions include vi-V-Vb/V-IV, or IV-Vb/V-V-vi aug-vi, or the reverse of this progression. It gives a really nice feeling, like a chromatic suspension. Again it's used often in Jap music, but not very often in Western music. About the only Western example I can remember offhand would be Closure In Moscow's "We Want Guarantees, Not Hunger Pains" at 0.27-0.28, in this video. Hear that awesome chord between the V and the IV, that is the secondary dominant in first inversion for you, in the progression vi-V-Vb/V-IV-iii.
That sums up this lesson. Always have fun composing, and do remember to experiment as much as you can with whatever weird chords you can find. Sometimes, you can make awesome discoveries by chance! Serendipity.