Replacing the diminished chord in a major chord progression?

Question by Daniel Duffy

I've been playing guitar for a while, but I'm just beginning to pick up theory (particularly chord progressions, with which your site has been extremely helpful), and at the moment I'm kinda analysing the chord progression in a piece I learned a while back, to figure out whats going on.

At one point, the key modulates from D minor to F major (the relative major I believe), and then plays a progression which goes Fmaj7add9, G5add9, Amin7 (which all makes sense), but then goes to a standard E minor chord, which is the is the 7th degree of the F major scale. Since this is F major shouldn't this be a diminished chord? How come it sounds AMAZING, even though the b note isn't in f major :)? And can you always, or is it common to (as I'm guessing this is what was done) raise the flattened 5th of that 7th degree chord to make it a standard minor chord and bend the rules this way? Thanks so much, any help much appreciated, and btw, you have an amazing, helpful site! :)
Daniel Duffy

Answer

Hi Daniel, first of all I do worry that some of my lessons may come across as overly dogmatic. I just want to stress that if something sounds good, use it. There is no right or wrong in music. There are no rules, just patterns and relationships that can be used as guides.

The diminished leading tone chord (the 7 chord) is just a "natural" occurrence in the diatonic scale. It is by no means a rule.

Sometimes you want your progression to sound natural, other times something completely outside the scale will sound more effective.

Secondly, let's look at your example...

Fmaj7 / Gadd9 / Am7 / Em

What we have there is a perfect example of the natural relationships of the C major diatonic chord scale.

C (I) / Dm (ii) / Em (iii) / F (IV) / G (V) / Am (vi) / Bdim (vii)

Look at the relationship between Fmaj7 and Gadd9. A whole step between two major chords implies a IV - V relationship.

So in fact, in this instance, E minor acts not as the 7/leading tone chord, but the iii chord.

This is confirmed by the fact that Em is a half step below Fmaj7, which is a natural iii - IV relationship.

It's further confirmed when the progression moves to Am7, which in relation to F and G major, implies it is the vi (6) chord.

I'd be interested to hear the piece to better gauge the context in which that original D minor chord is being played, because if we were to connect it to the Fmaj7 modulation, it suggests D minor is in fact the ii chord (if we're using C major as the diatonic key).

So just to recap...

Two major chords separated by a whole step implies IV - V.

A minor chord one whole step from the above relationship implies a vi chord (e.g. F, G, Am or C, D, Em).

A minor chord that occurs a half step down from a major chord implies a iii chord (e.g. Em, F or C#m, C)

Notice how I use the word "imply", because this is what you're essentially looking/listening for - a clue as to what relationships exist in a chord progression, which helps you decide what modes/scales can be used.

Let me know your thoughts using the comments link below. Cheers.