Harmonic mixing is the practice of using music theory in your dj sets.
You can use this knowledge to achieve specific functions when mixing two songs (similar to chord progressions), or to know which songs are compatible with each other, just to give a few examples.
The most common and basic form of harmonic mixing.
If you don't want to know about the ins and outs, just skip to "The basic and common form of harmonic mixing for dummies".
This is its most common and basic form, which tends to be the first thing to be suggested:
Song X is compatible with song Y if:
- Both songs share key signatures.
- Y's key is a fifth above, and both have same quality.
- Y's key is a fourth above, and both have same quality.
Sharing quality means that both songs are in minor, or both in major. There are many other qualities, but those two are by far the most common.
This means that a song in A minor will be compatible with:
- Another song in A minor, or a song in C major.
- Another song in E minor.
- Another song in D minor.
In short, you can mix a song in A minor with songs in: A minor, C major, E minor, or D minor. Don't forget that this is only the most common and basic form of harmonic mixing. Song interactions are much more complex than that, but this is a good rule of thumb that is a common place to start in.
Why those suggestions?
If you are not interested in the theory behind the suggestions, skip to "The basic and common form of harmonic mixing for dummies".
Short answer: The songs will be using either the same notes or will be using only one different note.
Long answer:
(In order to make this as simple as possible, I'll base all examples in either C major or A minor.) The explanation for each suggestion is:
- Both songs use the same notes. Both songs share key signature. C major is the relative major of A minor, and A minor is the relative minor of C major.
- A minor = A B C D E F G
- C major = C D E F G A B
Both songs share almost all notes but one, and that one note that is not shared is compatible with each other's mode (it sounds good).
- A minor = A B C D E F G
- E minor = E F# G A B C D
The difference is: F# or F.
F# is the major sixth of A. A minor with a major sixth instead of a minor sixth is the A dorian mode. It's a note that is very compatible with A minor.
F is the minor second of E. E minor with a minor second instead of major second is the E phrygian mode. Again, it's a note that is very compatible with E minor.
Both songs share almost all notes but one, and that one note that is not shared is compatible with each other's mode. (yes, same as suggestion 2).
- A minor = A B C D E F G
- D minor = D E F G A Bb C
The difference is: Bb or B.
Bb is the minor second of A. A minor with a minor second instead of major second is the A phrygian mode. It's a note that is very compatible with A minor.
B is the major sixth of D. D minor with a major sixth instead of minor sixth is the D dorian mode. Again, it's a note that is very compatible with D minor.
For completion, let's see a similar example but with a major quality.
According to our 3 suggestions, a song in C major will be compatible with:
- Another song in C major or a song in A minor.
- Song in G major.
- Song in F major.
The same explanations apply. Let's see a quick review:
- Songs share same notes (etc).
- C major = C D E F G A B
- A minor = A B C D E F G
- Songs share almost all notes but one (etc).
- C major = C D E F G A B (difference is F# and C D E F# G A B = C lydian)
- G major = G A B C D E F# (difference is F and G A B C D E F = G mixolydian)
- Songs share almost all notes but one (etc).
- C major = C D E F G A B (difference is Bb and C D E F G A Bb = C mixolydian)
- F major = F G A Bb C D E (difference is B and F G A B C D E = F lydian)
The basic and common form of harmonic mixing for dummies: using a circle of fifths diagram.
There is another approach to basic harmonic mixing. It has the advantage of being very simple, so it can be used by almost anyone without much music theory knowledge (if any). It has the strong disadvantage of limiting your knowledge to following a diagram. It won't get you further. It will make your set work musically, but you won't understand why, and you won't be able to advance in either harmonic mixing or music theory. I don't recommend this method, but I include it anyway for completion and because I know there are many DJs out there that don't have much interest in music theory.
It has only one simple suggestion. Follow this diagram:
The diagram works as follows:
Locate the key of the song in the diagram. That song is compatible with:
- Songs that have the same key.
- Keys that are to the side of your song's key.
- The key exactly bellow or above the key of your song.
In the case of C major the keys to the side are F major and G major. The key exactly bellow it is A minor. So, in short, your song is compatible with the keys in its immediate vicinity, the ones it shares a border with:
Most common and basic form of harmonic mixing, part 2 (includes part 2 for dummies)
There is an extra suggestion that is commonly made once part 1 is understood:
A song is also compatible with the 4th and 5th grade of the relative major/minor.
Explanation:
- C major = C D E F G A B
- A minor (relative minor of C major) = A B C D E F G
- D minor (4th grade of A minor) = D E F G A Bb C
- E minor (5th grade of A minor) = E F# G A B C D
Again, we see that C major shares almost all notes but one with D minor and E minor. The difference notes are Bb and F#. C D E F G A Bb = C mixolydian. C D E F# G A B = C lydian. The difference notes, again, sound kinda cool. They are compatible.
For dummies:
This adds two other compatible notes in the circle of fifths diagram too. Now the song is also compatible with the keys in its vicinity including the ones in the corners. C major is compatible with F major, G major, A minor, D minor, and E minor.
What this means for the circle of fifths diagram system is that two songs are compatible if they are neighbors in the circle of fifths diagram:
Beyond the most simple form of harmonic mixing.
We have seen a very basic form of musical interaction between two songs. It works, but if you want to do more interesting and less restrictive things, you have to go beyond it.
What is beyond? It is simple: knowledge of music theory and its applications to your instrument. In this case the turntables, the CD players, Ableton Live, Traktor, Serato, whatever you are using. Once you understand basic music theory you can apply it as you would with any other instrument. You can make progressions, you can make chords, you can make scales.
Let's see some examples.
We have song X in B minor and song Y in C minor. According to our basic suggestions both songs are not compatible, but music in real life is not that simple. Let's assume we are mixing the outro of song X with the intro of song Y. What is being played at that time, on each song? Maybe there are no tonal elements at all! Maybe there is only one tonal element on each song. If that's the case, maybe the only note that is being played in song X is B, and the only note that is being played in song Y is C. You can mix those portions of the songs and it will work. It's just a C and a B. If there is only one tonal element on each song, it will work. Which pair of notes do not sound good? It's when more than two notes interact when things get more complex, but even there things might or might not work depending on the specific notes that are being played on the moment of the mix, and not the overall key of the songs.
In fact, you might want to go beyond writing down the key of the overall song and start documenting the notes that are being played in the intro, mid, and outro of the song (or whatever division you can think of). That way you will not only know the keys of the songs, but the actual notes that are being played on a specific part. You can make chords and scales with this information.
This way you think about the overall keys of the songs as chord progressions, and the specific tonal dynamics of parts of the songs that are being mixed as tonal qualities.
Song X and Y don't have tonal elements in the parts you are mixing them, but they have tonal elements in other parts? Then think about them as chord progressions. They will sound well together, but will they work when the tonal elements of Y start? How will the change feel? Maybe you only had a few moments without tonal elements, and when the new music kicks in it won't work very well with the previous context. Maybe there was a long time without tonal elements and the context was long gone, so you can introduce a new harmony without much worry.
Another example: Song X is in C major and song Y is in B major. According to the suggestions we have seen, they are not compatible. We will mix the outro of X with the intro of Y, and the notes being played at the outro of X are C and E, and the notes being played at the intro of Y are B and E. C, E, B. That's Cmaj7 without the 5th! It, after all, might work!
Going beyond the most simple form of harmonic mixing is understanding harmony and music theory.