The Dom7 Chord Can Do What? (SURPRISE!)

How much do you know about using “Dominant 7th” chords? These chords can be used in pretty surprising ways. This lesson breaks down a very cool process for applying Dominant 7th's that most guitar players are totally unaware of...

For a lot of guitar players the "Dominant 7th" chord is a "Blues" chord, or it's a "Jazz" style chord. They seem to behave as if they’re just simply replacing major chords in many situations.

Other times, the Dominant 7th will show up in places where it does make make a whole lot of sense, (even if you have a basic understanding of chord harmony).

When these chords are used in unique ways, they still seem to sound quite good. Why is that?

In this lesson I’m going to help you better understand what exactly a “Dominant 7th” chord is, what it’s chord formula is, and what kind of relationship it has to the diatonic scale.


This chord is half major and half minor. It contains 4-tones, and if we analyzed how a Dominant 7th chord would be built from off of the root of “C” we would find that we’d get the Root Note, (C) a “Major 3rd” (E) a “Perfect 5th” (G) and a “Minor 7th.” Of (Bb). For that C7 chord type, again - the specific notes would wind up as “C, E, G and a, “Bb.”

Here’s what that chord would look like if we played it in the 3rd position…

Here’s what it would look like if we played it in the 8th position…

Finally, here’s what that would look like if we played it in the 5th position…

Now that you understand the chord tones, the chord degrees of each interval that creates the “Dom.7” chord, and now that you’re familiar with some chord shapes… we can start learning the different ways of how this chord is applied.

The first and most common application of this chord is generally using it as a “Diatonic” 5-chord that naturally exists within a major key.

This means that if we have a chord progression in the key of “C Major” we would find a “Dominant 7th” chord naturally existing upon that keys 5th step of “G.”

In this case we would refer to this idea as using the “Dominant 7th” as a “Primary” chord of the harmony. A typical Diatonic application in the key of “C” would work like this…

Alright, so now here’s where things are going to get to be a little bit of a surprise for a lot of you... Remember, earlier on I had said that a “Dominant 7th” chord is half major and half minor… that’s because they have both a major 3rd and a minor 7th interval within the chord tone structure.

This also means that aside from this chord functioning in its “Diatonic” “Primary” state, it can also function as a replacement for any other diatonic chord, (regardless of whether that chord might normally exist in harmony as a Major or a Minor within the key signature).

As an example of how we might go ahead and apply this, let’s take that chord progression we just played and replace the “Em” chord (in the second measure), with an “E dom.7” chord so that you can hear how this secondary dominant concept would be applied in that progression…

If you want to go and check out some real applications of the use of Secondary Dominant chords, you won’t need to look very far. They show up in a ton of different songs. You can perhaps start by having a listen to the song called, “I Can’t Tell You Why” written by the Eagles.

The Verse chord changes:

That piece is in the key of “D Major,” and in that songs 1st Verse we find simple chord changes that are fairly limited to using the two chords of; “D maj.” and, “G maj.” However, at the end of the verse, we find a chord from the key operating as a Secondary Dominant…

In that song the diatonic 3-chord of “F# Minor” is replaced at the end of the Verse with an “F#7”. And, later on in that song, the Bridge has the same situation occur once again in the same way.

Now, something else interesting is that the “F# dom.7th” chord is actually preceded by an “F#7sus4” so keep an idea like that in mind if you’re perhaps doing some composing using this theory on your own as well.

Another song you might want to look into is a song called, “Spooky” by the Atlanta Rhythm Section. That song’s in the key of “E Minor” and it uses a simple two chord riff that replaces the Diatonic IV-chord of “A Minor” with a Secondary Dominant application of “A dom.”

Also, in that piece, the dominant chord is performed with an extension of a 13th. The riff goes from an “Em7” chord and moves into an “A dom. 13th.”

There are quite a lot of different ways that these secondary dominant chords can be applied, but one thing is for certain. Any step of the scale for any key that you might be; writing, arranging or transcribing within (any step) can be performed as a Dominant 7th chord (it does not have to always be played as the correct diatonic major or minor).

At any time in any song, if it sounds good, you can replace a diatonic major or minor chord with a “Dominant 7th chord.” And, it can be played along with any suspension or extension that you would like!

As always, thanks for joining me, if you liked this video, please give it a thumbs up and subscribe for more on YouTube, (remember to hit that bell when you subscribe so that you’ll never miss any of my lesson uploads to YouTube).

Also, I'd like to let you know about the guitar courses over on my website at

I’ve got step-by-step; Beginner, Intermediate and Advanced courses that work alongside of in-depth elective programs to form the best guitar course available. The courses work to help you learn to identify what's required to get you up to that next level of guitar playing, in a very organized step-by-step way, that makes sense.

So, I look forward to helping you further at

Until next time, take care and we'll catch up again on the next lesson. Bye for now! 



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