I know a little bit of theory, maybe just enough to get me in trouble, I don't know. But with respect to the key you are in and figuring out the notes that are in that key I am pretty comfortable with tat. Like I just went through and for the key of B major, I know the notes in that key are B, C#, D#, E, F#, G#, A#, B. And I know that if I wanted to make a progression from that key, the chords I would use are Bmaj, C#minor, D#minor, Emaj, F#maj, G#minor, and A#dim.

Understanding all of that my question is if I wanted to throw an A7 chord into a progression, or construct an A# chord myself up the neck, like constructing the chord and having the root starting on the 7th fret of the d-string. Since as the way I know to make a scale and understand the chords of a key, there would never be an A7 chord in any key, so how do I know when it would fit in a chord progression? If there is a regular A-chord in a key can I just replace it for an A7 chord, or will that not always work? Is there more keys then just major and minor? Like is there a key of A7?

I don't know if I have buried my quesion is a stream of confused consciousness, but I guess my ultimate question is how do I know when I can use an interesting chord in a progression?
mm...not entirely. if you know how to figure out the diatonic triads, you use the same method to figure out the diatonic seventh chords. just remember to add the fourth third.

if, given the major scale, the diatonic triads are:

I, ii, iii, IV, V, vi, v*ii°

then the diatonic sevenths are:

IMaj7, ii7, iii7, IVMaj7, V7, vi7, viiø7.
(ø meaning half-diminished, in case you're unsure).

there is no key of A7, and replacing an A for an A7 (or an AMaj7 [or an a for an amin7]) will not always work. A7 is more likely to be in the key of D major (since V7 has a tendency to resolve to I), but that is not always the case.

how do you know when to use an interesting (which i assume to mean extended) chord in a progression? it's simple. play it. if it doesn't work, don't use it.
Anfangen ist leicht, Beharren eine Kunst.
Last edited by AeolianWolf at Dec 27, 2009,
Quote by AeolianWolf

there is no key of A7, and replacing an A for an A7 (or an AMaj7 [or an a for an amin7]) will not always work. A7 is more likely to be in the key of D major (since V7 has a tendency to resolve to I), but that is not always the case.

If you are wondering what to play over A7, though you would play an A Mixolydian scale. Being a Major with a flattened seventh, just like an A7 chord.

In my experience, you could almost always add a seventh to a chord that would usually have no extensions.

For example if your progression is A, D, E you could add sevenths on to make AMaj7, DMaj7, E7. E is the dominant chord in the key of A so it needs to take the flattened seventh as there is no Major Seven for E (D#) in the key of A.

in conclusion, depending on the original quality of the chord, you could add a seventh of the same quality and have it work (usually) in the context of the progression.

EDIT: to know when to play an extended chord in a progression, generally depends on the direction you are trying to go or the effect you are trying to make. Generally extensions are used to accentuate the melody line or to create bigger sense of finality or resolution. Or sometimes just a colour. For example Hendrix used a lot of #9 chords on the upstroke, and then went to the natural ninth on the downstroke... Although I think he was just a fan of #8 chords.. he used them a lot.
Last edited by mdwallin at Dec 27, 2009,
An A7 chord contains the intervals 1-3-5-b7. If in B minor (B-C#-D-E-F#-G-A) and you wanted to extend the triad built off the seventh degree, Amajor (A-C#-E), into a seventh chord, you would add-on the seventh degree from the A note (G).

You would then have a chord using the notes A-C#-E-G, the interval between the A and C# is a major 3rd, the interval between the A and E is a perfect fifth and the interval between the A and G is a b7. Thus this chord would be an A7 (1-3-5-b7).

using the same principle, building a seventh chord from the root of B minor would mean taking the notes B-D-F#-A, the interval between the B and D is a minor third, the interval between the B and F# is a perfect 5th and the interval between the B and A is a b7. This collection of intervals and notes would make the chord a Bm7 (1-b3-5-b7).

This is how all chords are built. Lets say you wanted a Major7#11 chord in C major. The intervals you would use are 1-3-5-7-#11.

Your C major scale is C-D-E-F-G-A-B, so if you wanted to build this chord from the tonic you would use the notes C(1), E(3), G(5), B(7), F#(#11).

Edit: incase you get confused, the #11 is reached by counting past the octave.

C-D-E-F-G-A-B-C-D-E-F-G-A-B

The F is the 11 degree, sharpening it will get you the #11.

Also, don't worry about F# not being in the key of C major for now, I was just using it as an example (you'll get to it when you're ready).
Last edited by MapOfYourHead at Dec 27, 2009,
I know a little bit of theory, maybe just enough to get me in trouble, I don't know. But with respect to the key you are in and figuring out the notes that are in that key I am pretty comfortable with tat. Like I just went through and for the key of B major, I know the notes in that key are B, C#, D#, E, F#, G#, A#, B. And I know that if I wanted to make a progression from that key, the chords I would use are Bmaj, C#minor, D#minor, Emaj, F#maj, G#minor, and A#dim.

Understanding all of that my question is if I wanted to throw an A7 chord into a progression, or construct an A# chord myself up the neck, like constructing the chord and having the root starting on the 7th fret of the d-string. Since as the way I know to make a scale and understand the chords of a key, there would never be an A7 chord in any key, so how do I know when it would fit in a chord progression? If there is a regular A-chord in a key can I just replace it for an A7 chord, or will that not always work? Is there more keys then just major and minor? Like is there a key of A7?

I don't know if I have buried my quesion is a stream of confused consciousness, but I guess my ultimate question is how do I know when I can use an interesting chord in a progression?

First of all let me commend you on how far you've made it in your self study of theory. It must feel good knowing and understanding chords and their relationships to scales.

In the example you asked for regarding an A7 - I'd see that as a bVII in the key of B. An A7 actually is V7 for the key of D, and you may find it wants to, or could resolve to D if you wanted to go that way. It is Diatonic to the B major scale, no, but who cares, there are lots of ways to play with chords in your writing to add a little something. a bIII for example sounds pretty cool a lot of times, also, you could try tritone substitution where you form a Dominant off the tritone (b5) of another Dominant, so for example, you could try an Eb7 in place of the A7, if you wanted. Lots of cool ways to tweak with different chords.

Theory helps you know when you are inside and outside the key. You can use an interesting chord any time you like, and I hope you have fun trying new stuff.
I am pretty well versed in chord construction, but thank you for taking the time to explain that. I was just more or less asking when it is structurly correct to throw in different chords other than the open chords or barre chords that a key would dictate. Take the most common chord progression known to man (Am, C, G). If I didnt want to make the 11 billion and 1st chord progression using this pattern could I change the Am to an A7 and the G to a G7 to give it a differnt sound(assuming it sounded good) If I did this would it still be musically correct, would I no longer be in the same key, if you were going to solo over it how would this change the scales you would think about using? Just basically what situation would you want to use unusual chords in and what are the other ramifications for using them?
Quote by Sean0913
First of all let me commend you on how far you've made it in your self study of theory. It must feel good knowing and understanding chords and their relationships to scales.

In the example you asked for regarding an A7 - I'd see that as a bVII in the key of B. An A7 actually is V7 for the key of D, and you may find it wants to, or could resolve to D if you wanted to go that way. It is Diatonic to the B major scale, no, but who cares, there are lots of ways to play with chords in your writing to add a little something. a bIII for example sounds pretty cool a lot of times, also, you could try tritone substitution where you form a Dominant off the tritone (b5) of another Dominant, so for example, you could try an Eb7 in place of the A7, if you wanted. Lots of cool ways to tweak with different chords.

Theory helps you know when you are inside and outside the key. You can use an interesting chord any time you like, and I hope you have fun trying new stuff.

Thank you, that helped a lot.
I am pretty well versed in chord construction, but thank you for taking the time to explain that. I was just more or less asking when it is structurly correct to throw in different chords other than the open chords or barre chords that a key would dictate. Take the most common chord progression known to man (Am, C, G). If I didnt want to make the 11 billion and 1st chord progression using this pattern could I change the Am to an A7 and the G to a G7 to give it a differnt sound(assuming it sounded good) If I did this would it still be musically correct, would I no longer be in the same key, if you were going to solo over it how would this change the scales you would think about using? Just basically what situation would you want to use unusual chords in and what are the other ramifications for using them?

first off, no, you wouldn't change Am to A7, because A7 is major in quality. unless, of course, you're going for that particular sound, but more likely than not you'll keep the diatonic third as it was in the original chord. if you change a G to a G7, provided all the notes (in this case, G, B, D, and F) are in whatever key you were originally in (pretty much just C in this case) then, yes, you're still in key. however, you could use that G7 to modulate into a different key. say you were in G major and you wanted to modulate to C major -- G7 provides a very easy way to do that.

technically, it is only STRUCTURALLY correct to use an extended chord if all the notes in it are in the key you're playing in. take your given progression, for example: Am, C, G. let's assume that this progression is in A minor (as opposed to C major). for Am, you wouldn't (structurally) use A7 or Amaj7 because they both contain C#, which is not in Am. for C, you would use Cmaj7, because C7 contains Bb and Cmin7 contains Bb and Eb, which are not in Am. for G, you would use G7, because Gmaj7 contains F#, and Gmin7 contains Bb, neither of which are in Amin. so, structurally, you could use Amin7, Cmaj7, G7.

but music isn't like architecture - it's fun to break the structure every now and then.
Anfangen ist leicht, Beharren eine Kunst.
I am pretty well versed in chord construction, but thank you for taking the time to explain that. I was just more or less asking when it is structurly correct to throw in different chords other than the open chords or barre chords that a key would dictate. Take the most common chord progression known to man (Am, C, G). If I didnt want to make the 11 billion and 1st chord progression using this pattern could I change the Am to an A7 and the G to a G7 to give it a differnt sound(assuming it sounded good) If I did this would it still be musically correct, would I no longer be in the same key, if you were going to solo over it how would this change the scales you would think about using? Just basically what situation would you want to use unusual chords in and what are the other ramifications for using them?

You can do nearly anything you want. Diatonic extensions are the most obvious things to do. Am becomes Am7. C becomes Cmaj7. G becomes G7. That is because those are the seventh chords built on those degrees which fit in C major, which is the key of that progression. Ultimately, you can do nearly anything which sounds good, however there are some non-diatonic things which are used fairly often, which work well, and are easier to find than just randomly hitting chords, until you find what you want. Here are some ideas to get you started:

Secondary dominants. You can play a dominant chord a fifth up from any diatonic chord, and use it to resolve to that diatonic chord. Instead of having your progression just simply Am C G, you could do: E7 Am G7 C D7 G. The chords E7, G7 and D7 are all dominant sevenths, and they all resolve down a fifth [or up a fourth]. Since its in the key of C, the G is the primary dominant, as it resolves to the tonic. E7 and D7, are non-diatonic, and called secondary dominants, because they do not resolve to the tonic. The secondary dominants are analyzed as V/[chord it resolves to], so E7 and D7 would be V7/vi and V7/V, respectively in C major.

Tritone substitutions. You can replace any dominant chord with another dominant chord a tritone away. These two chords have the same function. In a V7 chord, the third and seventh are a tritone away. A tritone is dissonant, and is what gives the dominant chord its characteristic tonality, and provides the resolution. A tritone is also half an octave, so when inverted it is still a tritone. Thus, there are two dominant chords with the same tritones in them [they will have enharmonic spellings, but that's not important here]. The B and F tritone in a G7 tritone is the same tritone as between F and Cb in a Db7. These chords can be subsituted for eachother, and are a tritone apart. So, you can change a Dm7 G7 C progression to Dm7 Db7 C7, which has a nice chromatic root movement. The tritone substitution is analyzed as bII.

Secondary tritone substitutions. Combine the top ideas, and you'll realize that you can use dominant chords a semitone above any diatonic chord [or any chord for that matter], to resolve to it. Your progression could become Bb7 Am Db7 C Ab7 G. These are analyzed as bII/[chord it resolves to]. Your progression would have Bb as a bII7/vi and Ab7 as a bII7/V.

Chains of dominants. You can make a dominant chord resolve to another dominant chord, which can in turn resolve to another dominant chord, etc... until you get to the major or minor chord you want to end on. You know that a dominant chord can resolve either a semitone or perfect fifth down, so you can use this to make strings of dominants.
I am pretty well versed in chord construction, but thank you for taking the time to explain that. I was just more or less asking when it is structurly correct to throw in different chords other than the open chords or barre chords that a key would dictate. Take the most common chord progression known to man (Am, C, G). If I didnt want to make the 11 billion and 1st chord progression using this pattern could I change the Am to an A7 and the G to a G7 to give it a differnt sound(assuming it sounded good) If I did this would it still be musically correct, would I no longer be in the same key, if you were going to solo over it how would this change the scales you would think about using? Just basically what situation would you want to use unusual chords in and what are the other ramifications for using them?

Here's a freebee.

In any given key I like to highlight 13 chords that you can play around with that add variety, and can help take things in a new direction, and which create slight dissonance, but add interesting flavor as well.

You have the big 7 diatonic chords of course.

Then you can use what is called reverse polarity - you take the ii iii IV and you reverse their qualities, into a II III iv - Beatles did this all the time, going D to Dm in the same song for example.

Then you can make a bIII bVI and bVII.

So with 13 chords in a given key you can play around with and see what you like - some outside stuff there but not that far outside. I just recommend using one and not the other in general, for example, use rev polarity but then don't use the b approach in general, because it can tend to sound muddier and ambiguous.

Now harmonically these chords can be analyzed in a lot of ways, for example showing what key they borrowed from, or what modal quality they suggest, but the idea is that you can play in and out of these ideas pretty well, with some outside sounding notes, and a lot of inside ones, and simply by using your ear you can break some "diatonic ruts".

How to approach them, from the outside, triad theory for example if I'm playing in C major but I use reverse polarity on the ii and make it D, then I'd want to make sure that I accent the F# on that chord, and not create a minor 2nd dissonance by playing or emphasizing an F over F#. Knowing your triads and what notes make up any given chord help you outline your solo and chord tone approaches, and create some interesting melodies that will sound different, because they are outside the diatonic harmony, but will work because they are in cohesion with the underlying chord at that moment. So, you might end up with some cool melodic interval jumps that you'd never have found by ear alone.

Hope this helps.
Last edited by Sean0913 at Dec 27, 2009,