4 Ways Harmonic Mixing Can Rescue Your DJ Sets


Try what you want to deflect it, sometimes you may have no choice but to play patrons' requests. Getting it done without ruining your DJ set is one thing harmonic mixing can help with. Pic: No Breasts, No Requests

Back at the start of my DJ career, I read a book called How to DJ Right: The Art and Science of Playing Records (I completely recommend it to any new DJ, by the way). Of all the styles of mixing it discusses, the one that I grabbed and ran with the most was harmonic mixing, which opened my eyes to many mixing possibilities.

This isn't the place to explain harmonic mixing (head over to The 123 Of Mixing In Key for that), but the absolute basic is that every song has one main "note" which it comes back to over and over again - and some "notes" mix well others. (It's a bit more complicated than that, but as I say this isn't an article to explain it all. You get the idea.)

Now, some "notes" clash when you try and mix, and some don't. Knowing the "notes" or "keys" of your tracks is the basis of harmonic mixing, and this is what helps you to prevent most key clashes. (There is software to work this out for you, like Mixed in Key, beaTunes and others.)

Notice the word “most”. It’s not foolproof. Yet, most times it works accurately. There are four benefits I find time and time again to at least considering mixes that are "in key" (or "harmonically matched"). Here they are:

Four ways harmonic mixing can rescue your DJ sets

  1. It can prevent trainwrecks - Not BPM trainwrecks (when the beats are completely out from each other), but musical trainwrecks where the music clashes horribly. Even some of the best DJs sometimes throw a song on, unprepared for the key clash that ensues. The last thing a hardworking DJ needs is folks flashing obscene gestures because they cause a musical trainwreck as they try and get from one tune to the next
  2. It helps prevent you picking the same songs over and over - Many times during gigs, temptation begs me to play the same songs in the same order I played during a previous gig. So to avoid this, instead I search for a different song in a matching musical key that might be good instead. Usually, I find a song I never thought of playing. Sometimes when I do this, not only do I receive a huge positive reaction from patrons, I also find myself surprised the sh*t worked in the first place!
  3. It means you can often successfully mix genres - As you’re playing a current hit, someone asks for an 80s new wave song. This is how I handle it. First, I look at the key, or "note" of the request. If it matches the current song’s key, rather than try to deflect the request, I just might play it next. If not, I remember the key of the requested song so I can mix it later on when I am playing a different song in a matching key
  4. It lets you break tempo rules - A good rule of thumb (from the book I mentioned earlier) is to always mix plus or minus 4 BPM from the current tune. Yet, I always don’t do it. Imagine playing a song at 128 BPM. A patron insist you play a song that plays at 95 BPM. How do I work around it? Well, if the key matches, I often choose to play the requested song next. Trust me, many folks won’t get pissed about an immediate tempo change… if the keys match. Or I can work my way down in two steps using two keymatched tunes (maybe another song at 115 BPM first). If I followed the tempo rule, it would take me forever to play the requested song. As it is, drunk people are already annoying. At least, without ruining your set, this way you go ahead and play the damned song next, shutting them up as quick as possible. The drunk person might even tip you...

This is only one tool...

It's important to remember that harmonic mixing is only a blueprint, an extra option open to you. Non-matching songs will work well in your mix too! I also can’t promise this will make someone an excellent DJ. Only practise does that.

But especially if like me you're a DJ who works in an environment where you're expected to take requests and play multi-genre, multi-tempo sets, you'll find that harmonic mixing is often a godsend.

• DJ Stone Crazy is a DJ from Central Florida, USA. Here's his blog.

Do you use harmonic mixing in your sets? What's the biggest advantage to doing so for you? And what have you found to be the pitfalls? Please share your thoughts in the comments.


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  1. Dj RB0t says:

    I have that book :0

  2. DJ Squared says:

    I have to say I feel just the opposite as you. I find (at least for me) that beatmatching is far more important the Key matching. People will generally be more OK with a genre shift if it is beatmatched. Now admittedly, I don't key match...I can hear key differences but I don't go out of my way to match them. Now obviously if you can beat match and key match, that is always the best. But at the end of the day, do what works for you.

    • You're right. Whatever works for you.

    • Pidanha says:

      Maybe not aware of it but I pretty much think we all do, even if they are unaware of it or don't know even what a Key is or what does it have to do with the songs he is playing...

      But we are always on the search of "songs that sound good together" and sometimes you get them, that they blend seamlessly into each other and I was amazed -personally haha I think I was still a kid then- when songs I had already marked in my head as 'compatible' turned out to follow these simple rules of key matching...

      Now, when people are fixed about keys, these softwares as I've tried, sometimes get it wrong, and without a good ear you wouldn't be able to tell which key it is in... And even tho it becomes 'easier' to mix one song with another, sometimes you could use the element of surprise w another key, or who says its not ok to mix songs with different keys? Its you, and you only know where you want to take people w your music

      Sorry for the long comment, haha

      • THANKS for the long comment! One thing about key locking is that it can stop you getting stuck "between" keys, where things are just half a note off and there's not much you can do about it.

  3. Ooooh, how much better would clubbing be if more DJs out there understood the concept of key matching - or at least had some sense of what clashes too much for the crowd to bare.

  4. Finlay Stewart says:

    For me its just another way to sort tracks, like BPM, date added or genre. It's handy to know (in advance!) when things might not sound right, but it's never stopped me picking a track. It's guidance, a helping hand if you like.

    Sometimes for a recorded mix I might make more of an effort to key match, but live the right track is more important than the right key.

    I'd try damn hard not to drop 4 BPM between tracks though, the energy would drop too, I'd slip a couple of BPM off a track and see where we are, or I'd find a Get-out-of-jail-free crossover transition track. I tip my hat to DJs who can get way with that.

    • I don't always get away with dropping too low. Sometimes, I get caught.

      • Finlay Stewart says:

        Hey sometimes is pretty good, I'd get caught every time! I always surprised how much you can alter the bpm of a track that's playing and no one notice. If you are going to drop a few bpm between on track and another and quickly cut between them, then trying to get them in the same key is definitely a good idea.

  5. DJ Forced Hand says:

    One word... "LIKE"

  6. A question about harmonic mixing:
    When utilizing the key lock function, is it possible to turn key lock off, adjust the tempo (and therefore key), and then activate key lock so that the song gets locked in the altered key and the bpm can be manipulated without changing the key?
    Put another way, can I take a song that's in C, adjust my tempo +6% to put it in D, then key lock it in D?

    • That's a good question, and usually, no. However, some software like virtual DJ has a separate knob to adjust key without altering pitch, achieving the same thing.

    • I was curious about this as well and, as far as I can tell (and my ears), this does seem to be possible in Traktor. If you turn key lock off, adjust the pitch +/- 6% and then turn key lock back on, it holds the new key even with changes in bpm. You can try and mix it into a song with the same (new) key and it seems to be in the same key (e.g., I started with a track in 1A, increased the pitch 6%, then mix into a song in 8A (add 7 on the camelot wheel) and it sounds perfect).

      It seems a like a good way to pitch up vocal samples on the fly and in key.

      Correct me if I'm wrong!

  7. I've never paid attention to a song's keys when mixing, but I might just give it a try. One question though, how do you know what key the song is in? I mean, personally I can roughly find out what song a key is through careful listening (a skill acquired through music theory classes and years of playing instruments), but how would an average Joe find out the key of a song?

  8. Try out Ableton's Note Spectrum! It gives you the notes of the song thats playing!

  9. Stavros says:

    The idea is awesome, full stop. However the software that do it at the moment need waaaaaaay big improvements. Rant starts:

    I tried demo versions of the 3 major ones with the best intentions, unfortunately none convinced me.

    Mixed in key: nice and simple, love the camelot wheel, but why wont it fill in the values in the id3 tags in the appropriate fields, so that they can be seen in virtual dj, windows explorer and other programs? IF only it did that...oh, and coming up with suggestions from the already analized songs would be good.

    Beatunes: Slow, on a pc anyway. slow to scan, slow to use...slow. Also why can i not open a playlist or a folder? And why wont it export m3u? m3us been around since the dawn of time. Too itunes orientated. I installed itunes and quicktime just for this but it's not for me. sorry. I like the idea of suggestions of songs that match. times i thought....oh never thought of that...lets give it a shot. inaccurate though. how can it give different values to dupplicate songs? Also camelot system is better.

    Rapid evolution: I only tried 3 which is betta at the moment. seemed very slow analyzing songs. didnt have the patience. should i try 2? its free though so thumbs up to that

    In other words i tried these programs to help me build better playlists. especially cuz i play different genres for mixed crowds (that usually like older cheesy music :-( ) but i caught myself doing things the old way as this was taking too much time and frustratiion. hope the next versions work for me. rant over

  10. I use BeaTunes and although it is a slow program, with skill an patience it does a great job at finding keys and creating key/color playlists. I don't think it gets deserved credit. Maybe I'll write a tutorial on how I use it....Phil?

  11. As a long time user of MIK, I use it for preparation for a gig or mix cd. It helps me sort out what vibe I want to play. Having tracks ready to go at a party also helps prevent the possible harmonic trainwreck. without getting into the details of MIK, sometimes you have to break the rules of harmonic mixing,creating a key clash, in order to raise the energy, or lower it at the appropriate time ( I keyed a mix I did many years ago, 90% of the tracks were in key. The other 10% still fit the vibe of the mix). Harmonic mixing is a very useful tool, with the right practice and use, it will take you mixin to another level.

    • Have to agree with you. Harmonic mixing could be and it is great, but just following the "rule" can become quite annoying to the crowed/listener.
      At some point, like you said we need to create a key clash, a powerful kick to raise energy.

  12. reason808 says:

    Maybe I've been blessed with a good ear, but I can usually guess when songs will match harmonically. 9 out of 10 times, I'm right.

    I always preview it in the headphones first, and if I'm wrong, I can easily choose another song or mix on the drum-only intro that's usually there.

    Harmonic mixing is a cool technique but I don't feel its worth re-analysing and sorting my music collection over. Especially when my instincts are usually correct. Anybody else feel the same way?

    • My guess is that it's not your good ears that allow you to tell if songs will match or not. It's that basic understanding of the way music works. In my opinion that's one of the most important skills a DJ should have, but in reality, many just don't. I've been to so many club nights with DJs that just didn't know or didn't care, and that's usually also the type that just slams out track after track without ups and downs or any concept at all. If you're not one of those DJs, and you know your song collection well, you probably won't need key detection software and prepared sets for any given night.
      Mind you, key matching with the help of software can be very useful for situations like Stone Crazy has described them - like "how in the world do I get from this Top40 commercial RnB song to that 80's wave song without killing the flow"?

      • Again, I agree with everything Jimbob says.

      • Stavros says:

        how in the world do I get from this Top40 commercial RnB song to that 80′s wave song without killing the flow”?

        The answer to that for me is mashups. im not good enough to make my own, but its what ive been using so far to change genres especially to/from older music. its like an intro to what's next. and if I can get them in the same/matching key that's a bigger bonus. another option is covers, but then ppl come and say...oh the original was so much better...yes i know, but have you heard this one before?

    • You miss out on being shown 10, 20, 30, 100 tunes that will very likely all mix on key with the current one by not pre-analysing, especially as it's simple to add this metadata and one click to sort once you have.

      • reason808 says:

        Sorry not to reply to all the helpful comments.

        I did have a bit of musical training in Jr High & High School before it hit the punk rock DIY attitude. That's probably a part of it, but most of my melodic hunches have been correct.

        @Phil: I think I'm having metadata overload! I'm trying to catch on up my digital collection. Buying lots of missing tracks plus cue & tag work during my limited free time these days. Harmonic tagging feels like the straw on the camel's back right now. But I will take a second look once I'm settled more.

  13. soundcloud.com/lewislace

  14. Ive been mixing in Key for a little while... I find it adds an extra bit of clarity to the way I mix... Before I knew about it I would have music clashes in my mixes... now I can almost hear the way the keys are by ear and match it with something ... gonna have to check this book out

  15. Using beatmatch and mixing in key has taught me a lot. It also saved the day yesterday!

    Asked to play, and keep playing, a load of stuff from a fairly unfamiliar era to me I found myself looking at compilation albums of tracks that I didn't recognise at all.

    My Digital DJ Tips reading came to mind and I just played them by BPM then by key. The result was harmonious and kept them all happy for the evening. Phew, escaped again! Thanks Phil!

  16. Great discussion. I discovered mixing in key way back in the 80's and it has been a great tool to add to my tool set. Beatmatching is very important but beatmatching with harmonic key mixing is twice as effective. With each key structure one can begin to set the mood in your whole set (Up or down). More importantly utilizing harmonic mixing will make it easier in finding perfect mixing combinations that bring that special effect you are looking for. Anyway here are my two cents.


  17. Mixed in Key was the best purchase I made in a long long time. It doesn't always work 100% but if has made building my podcast/show tracklist soooo much easier and faster! As a result my mixes sound much clearer and harmonic and that has helped me rank really high on Proton Radio's Top 100 DJ mixes. I'm currently at number 14 there alongside big names such as Digweed, Hernan Cattaneo and Eeelke Kleijn :)
    Kontrol S2 + Mixes in Key = all I need to put out great mixes :)



  18. I was wondering if there's a software that will sort the BPM and Keys and put them together to make it easier when trying to find songs to play.

  19. I'm all for harmonic mixing but I've been searching for the best way to make bigger BPM changes without too much of a negative impact on sound quality. I hear some of the big DJs pull off massive BPM changes and the sound quality still sounds great.

    I've been playing around with ableton's complex pro which seems to do a pretty good job. Anyone have any tips on how to get the most out of for DJing such as adding EQ3 or limiters?

  20. I have playlists/smart crates on my iTunes library w/the + or - 4 BPM rule in mind and they all have the key note in "comments" box where I can list it from lowest to highest key note or vice versa. So I'll click on any crate, say 101- 104 BPM, that has 150 tunes of various genres & scroll from key note 1A on down. Advantage of this method, I find my mixing is somewhat smooth (still learning), but disadvantage is that I'm staring at laptop screen a little too much than I'd like.

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