Reharmonization – First Steps

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Reharmonization. It’s kind of a funny word when you first encounter it. It means exactly what it sounds like. To reharmonize something is to alter the harmony, and when we talk about harmony we’re really talking about chords. So to put it plainly, to reharmonize something is to change the chords. Why would a musician want to change the chords to a song? And why not change the melody, too? And most importantly, how does one go about changing the chords to a song? Can you just choose any chords you like when reharmonizing? In this article we’ll answer all of those questions – and more.

Reharmonization – Why Change the Chords?

First things first – let’s discuss why we do NOT alter the melody, and instead concern ourselves with only the harmony. The melody is the most recognizable part of the song, the part that the listener walks away humming. Changing the melody of a song is really changing the actual song, so we tend to leave the melody alone. But changing the harmony can allow us to drastically affect the sound of the song without actually changing the melody. This allows the listener to hear the same melody they are already familiar with in a fresh, innovative way. “Reharming” a song (short for reharmonization) can create an entirely new mood and character, and this is a very powerful and creative skill for musicians to have. Orchestrators, composers, and arrangers all practice the skill of reharmonization regularly.

Reharmonization – How Do You Do It?

Reharm is a very dense topic, and can be a very advanced skill. But it just takes a little bit of practice to start developing some reharm tools. Let’s start with a very simple song that we all know – “Happy Birthday.”


Notice how simple the chord changes are – F major and C major, which in the key of F represent the ‘I’ and ‘V’ chords.

We’re going to alter the chords – meaning we may change some, remove some, or add some. We are not going to do anything to the melody. Let’s start with an easy one: in measure 2 and 3 we have a ‘C’ major chord. We can change this to a C7 chord in measure 3, which will act as a ‘V7’ chord going to ‘I’ (the ‘F’ major chord) in measure 4.


Ok, now let’s add another chord to this progression. It’s very common in jazz to precede ‘V’ chords with a ‘ii’ chord, creating a ‘ii – V – I’ progression. Since we have the ‘V7’ chord in measure 3 we can precede it with the ‘ii’ chord, which would be G minor.


Lastly, we’ll reharm the resolution of this ‘ii – V’ progression. Instead of playing Gm7 to C7 to F major, we’re going to play Gm7 to C7 to D minor 7 (sometimes referred to as a “backdoor ii – V”). Why does this work? Look at the notes that F major and D minor have in common, and remember, too, that D minor is the relative minor of F major.


Now listen to the original and the reharmonized version:




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Welcome Paul Buono

Paul Buono has returned to the JazzEdge family as an instructor.  His professional piano/keyboard experience includes national and international touring, university professor, musical director, pit

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  1. I get it! But need to work on being accomplished at recalling the relative minor of every key first.

  2. I think I understand the reharm. But, I’ll have to work on the stride in the left hand. It will take some practice to move from the root to the chord smoothly.

  3. The ii-V-I part is both understood & sounding great. The replacement of I by vi is understood too but the resulting sound in measure 4 is just disliked by me. So why bother to reharm with relative minor in the first place?

    In fact, substitution by tritone as separately introduced by you in other reharm lessons, such as Gm7 – Gb7 – F in measures 3 & 4 for this song, is likewise understood but not welcome by my ears. Are my ears too conservative then?

    1. Tritone substitution is something your ear needs to get used to. Kind of like cooking: if you take a basic recipe and then add basil to it you will learn what adding basil will do to the food. So if you play tritone substitutions and listen to tunes that have tritone substitutions you will learn what musical mood they set and eventually will just know when they sound cool.

    2. Your ears’ politics are a function of what they are accustomed to listening to. A lot of what is on the radio stays within the guard rails most of the time. Jazz and the classical music from which it draws push boundaries. That sound will provoke a different emotional response, no doubt, but whether you enjoy that response, whether that response evolves and how you enjoy that response over time will vary with the individual. I played a familiar church song written in a major key at a funeral once where I started out in the relative minor key. The emotional impact of the change to major key was huge (contrast creates interest). The change to the unfamiliar and resolving with the familiar created a tension and release that was highly effective. The whole point of reharmonization is purposeful contrast with either the listener’s point of reference or a theme that you established previously. But if you’ve played a single song ad nauseum in a cowboy bar to quiet the folks yelling, “Play something we know”, you know that now everyone enjoys straying from the familiar.

  4. This is a helpful article, especially having you play the music so I could hear it and not simply read about it.

    In case this is useful information, it would have been a bit less confusing if the key signature was there, or if you had said you intentionally didn’t put it there — I initially was confused, thinking the piece was in C, not F.

    Thank you,

  5. Thank you, this is very helpful.
    I know you are very busy, however I appreciate the tips that you give to help us all become better musicians