Making tempo changing

1. Use the 50% rule… – This one is pretty simple, and it states that if you’re beatmixing, say, a 120BPM tune into a 126BPM tune, the best place to do that mix is at 123BPM – 50% of the way between the two. That way, the first tune is only speeded up a small amount, and likewise the second is only slowed down a small amount. Fewer people are likely to notice when a tune is “off” its original BPM when you try to stay close to the original BPMs in this way
2. …and the 5% rule – This one states that you should only deviate by 5% up or down, maximum, when beatmixing (I usually prefer 4% personally). So if you’re mixing a 100BPM tune, 5% down is 95BPM and 5% up is 105BPM – so you’re looking for your next tune to be within that range. If all this talk of percentages muddles your head, just choosing 5BPM up or down (or a 10BPM range) is a simpler, if slightly less accurate, way of remembering this rule
3. Use key lock… but beware – Keylock, or master tempo, is the control on CDJs and DJ controllers/software that stops the pitch of a tune altering when you change the tempo. It can be highly useful when executing BPM changes in a beatmix, because it stops tunes sounding ridiculously low or high when you slow them down or speed them up outside of a subtle change. However, deviate too far from true tempo (or sometimes, any distance at all) and the sound can reduce in quality with keylock on, so trust your ears. A good rule too is to try to return to the true tempo for the incoming tune once you’ve finished your mix, and then turn key lock off once you have (say, within the first minute of the tune playing), by making slow BPM adjustments that hopefully your audience won’t notice
4. Make those BPM adjustments randomly/off the beat – It’s fine to adjust the BPM of the tune that’s playing as I just described – indeed, it’s the only way you’re going to move between the BPMs if you also want to carry on beatmatching. But doing this in slow increments over a couple of minutes is the best way, as hopefully your audience won’t notice. Another tip is to make these small adjustments randomly or off the beat. The reason is that because most adjustments we make in DJing are on obvious “1” beats; so if you do this in totally random places in the song, there’s nothing musical about it (ie the audience isn’t expecting anything to change) thus you’ll get away with it better
5. Try the double/half trick – If your set speeds up to a high BPM (say 155+), you can mix in a tune that’s exactly half the BPM of the playing tune and the beats will line up (so from 156, you could mix into a 78BPM tune) – great for hopping from dubstep to hip hop or vice versa
6. Ditch beatmixing totally – It ain’t all about beatmixing, folks. A couple of the best tricks up any DJ’s sleeve are surprise and silence. Surprise the audience by radically changing genre and BPM at just the right time by just throwing a new tune on right at its biggest hook or drop. Or, kill the music totally before dropping in to, say, an acapella at a different BPM, then a beat finally to bring the music back, again at the new BPM. Or you could cut from the beat of one track at one BPM to a beatless break of another at a different BPM. Sure, you’ve got to practise such techniques (and sometimes, you’ve got to have the balls to practise them in front of a real audience) – but these are all bonafide tricks for moving between the BPMs without needing to religiously rely on beatmatching
7. Trust your ears! – we have three full sections of videos on mixing, we have an example mix where I demonstrate going from a full-on house tune to a laconic lazy reggae song in one mix – while still beatmatching! This particular mix breaks pretty much all the rules above, but it still works… so the important takeaway here is to trust your ears and if you experiment and something sounds good that shouldn’t (or if try as you might, a mix that ought to work really just doesn’t) – believe what you’re hearing. There’s art as well as science in mixing, and never more so than when boldly chopping around genre and tempo ranges