Quick Tip: Harmonic Mixing
Most DJs have developed an ear for music, and when listening to a song or mix that is off-key, a mental alarm is triggered and it will sound musically bad.
Other DJs dont know about this important technique play it safe and mix during the drum breaks so there are no harmonic clashes. While this is a clean, fail-proof method, it leaves a lot of magic moments on the table. Key matched mixing, including major/minor or minor/major flips, present an exciting way to truly “mix” music.
Without getting into the details of music theory, it's true that any musical key you choose shares a special harmonic relationship with certain other keys. There are other key combinations that work outside the harmonically compatible group.
Here are examples based on the Camelot Wheel:
A minor > B Major
E minor > F Major
B Minor > D Major
F Minor > A Major
C Minor > E Major
G Minor > B Major
D Minor > F Major
A Minor > C Major
G Major > E Minor
D Major > B Minor
A Major > F Minor
E Major > D Minor
It's not always compatible, so you have to experiment with individual songs before you bring it into a set, but some songs will sound insanely cool when you mix them like this. Tracks with simple melodies usually yield the best results; if they're too complex, your mix can go off the rails.
So if we can go from 8B to 9A, why can't we go from 8B to 7A? The scales of 8B and 7A contain dissonant intervals, so the mix wouldn't work harmonically.
Again, it's important to keep in mind that mixing harmonically takes a bit of preparation before your gig. As we discussed in Chapter 2, once you've labeled your tracks using the Camelot code, you can move quickly from one song to the next by simply glancing at the key code. But moving around the Camelot Wheel to do harmonically related mixes, like the ones we're suggesting here, takes practice.
The frequencies that create the nastiest harmonic clash are the low to low mid frequencies (i.e. bass) so it's always worth using the EQ effectively and in an intelligent way. The low frequencies are also more prone to phase cancellation so it's always a good idea to control the bottom end of the mix.