I am just about the last person you want to ask how to DJ; I don't know squat, I'm not even very good at beat matching (yet – practice practice practice) yet there's little enough written about techniques that I can find here on the intertubes.
So I'm thick-skinned and hard to embarrass, and figured that I might as well write up what I've figured out so far, and got from others by bugging them, and share what I've learned so far.
Many thanks to Albert Santoni for the tips!
Your equipment and setup will surely be different from mine; but there are a few things that are pretty much required before you start.
You need to have two stereo channels, one for main output to speakers, and another for your headphones. See the diagram to the right. I decided right from the start that my entire music collection and equipment would be all software, with as few control surfaces as I can get away with; my days of collecting the coolest and latest hardware are long past. At the moment, I am using a Hercules Control MP3 (the cheap one; requires funny compile options; see how-to's) and an inexpensive dedicated sound computer. The built-in soundcard I use for my headphones, and I bought a top-end soundcard, the M-Audio 2496. I also have a pair of Mackey powered monitors that are my (entire) sound system.
I assume you know that the idea is, you have a track playing live (the “outgoing” track), and you are readying a second track to mix in then switch to (the “incoming” track). You can do this to all sorts of ends, but a common one is simply to have a continuous stream of music, smoothly switching from the end of one song to the beginning of the next. The basic technique is the same however so start with that as the simplest example.
The idea of course is that the outgoing song will end soon, and you want the incoming song to start precisely as the current one ends, possibly with some overlap, such that people dancing or listening do not experience what is known as a train wreck, eg. two songs playing at once not synchronized in time and place. You will become experienced at making train wrecks, I know I have.
Clearly, goal is to get the incoming track in sync with the outgoing track; both in time (beats per minute) and place (downbeat in a measure at the same time), so that when you slide the mixer to the incoming track people are pleased, rather than run from the room, hands over ears, screaming.
This is difficult. It can only be described so far; the act it aural and tactile, and you just gotta go do it.
I suggest that initially that you mix a song with a copy of itself – since the first thing to learn is the 'mechanics' this will eliminate differences in song beat and structure. I play mainly trance music, which has the advantage for mixing that the beat is the same from one end of a song to the other, and also tends to have nice repetitive structures to play with.
Start playing the first track in player 1, “live”. The mix slider should be to the left. Once it's playing live, it's “outgoing” – meaning it will end soon enough.
Load the new (incoming) track into player 2. If it's the same as the outgoing (playing) track you can skip the BPM matching part (described below).
While the first track is playing live, click/press the HEADPHONE button for player 2. Now you need to find the spot where you will eventually want the incoming song to start; it's not often the very beginning of the track, which might be silence, instrumental preludes, intro vocals, etc. Usually there's some sort of first downbeat. Find that.
To find song start, play and listen, or turn the jog dial if you have one, or click-and-drag in the waveform display for player 2. You will have to jockey the track back and forth to position it to right before the start of the first downbeat (or whatever your play point will be). With player 2 paused press CUE. This sets the current point as the CUE POINT.
(Player 1 is still playing… the song will eventually reach the end. The pressure mounts… you gotta get ready to start the next song before the first ends… it seems you'll never have enough time to get this done, but you will – with practice. If you run out of time simply restart the “current” song.)
Ideally, when the outgoing track is a few measures from the end, or is starting its fade, or where ever it is you want to switch to the new track, … but for practice, mentally sync with beats, and on the downbeat to a new measure, press PLAY on player 2.
It is almost certain that incoming is not in sync with the outgoing. No matter, that's what you're here for. This step, to me, was very difficult to learn, and still occasionally boggles. You have to hear the beat — dum dum dum dum … – in one ear, and determine if the new track's beats are early, or late, with the other.
If they are very close, it's not too bad to get perfect. The worst, for me, was when they were almost exactly half a beat off… as you improve, this will happen less, don't freak out, persist.
The outgoing track is playing live, and you're hearing the incoming track on the headphones. Jog (dial if you have one, or click-drag in the waveform, or temporary pitch-change buttons, …) the new song to better align the new song with the current. The waveform display helps (line up the peaks and you'll be very close) but I found that I'm better off doing it all by ear; there's a real tendancy to get all geeky with the display when you should be listening – this is music, remember? – keep it in the aural realm and I think you'll be better off.
As the beats get very close, it gets easier to align them; when the beat sounds “doubled” you're practically there.
If the two tracks are at all compatible (they should be if it's the same track in player 1 and 2) the two tracks should sound good mixed together, or at least not sound bad!
You can “peek” with your headphones off, and tentatively slide the mixer to the right, mixing both tracks in the live channel. Bad idea live, fine while learning.
If it's OK, start sliding the mixer to the new track. The speed at which you do this depends on all sorts of subjective factors – but if it sounds good do it. Trust your ear.
Abrupt jumps from one track to another are tricky, but can be done.
Practice, practice, practice. A lot of this is what I call “mechanics”, having your hands know where controls are without thinking, knowing how the software reacts to controls, and when to do what. Once you gain control over that stuff, you can think more about the music itself.
N00b warning: At first, it was enough to get beats aligned, at all; getting two tracks aligned at a measure (in psytrance, measures are 32 beats long) took a lot more effort to learn. Getting beats matched before the current track ended, scary A few months later, lo! I find myself with enough time to think about incoming song structure, maintaining a groove, all sorts of non-mechanical things…
To do a decent job of it, you have to know when and how the current, outgoing, song ends, so that you know when to mix up the new, incoming track. Except for the very first song of a set, I do this after I've loaded up the new incoming song. Soon enough, the incoming song will become the outgoing song; you want to gain some knowledge now for that future time.
If you are trying to maintain a consistent beat, tempo, emotional flavor, etc, for say, a dance floor, you should know the structure of the songs you're playing. Often tracks have long quiet sections that make for nice punctuation for listening, but might ruin a dance floor groove.
The mixxx display always has a small, low-res waveform graphic that you can see the loudness profile of the track over all. You can click in it to navigate within the song. Check out breaks and quiet spots and listen to see if it's compatible with the sound you want to make. Consider the re-up-take of the beat after those quiet spots to be places to mix into.
If you're unhappy with your choice of match-up points for the new incoming track, pick another.
And always check the end of the track or section to see what it sounds like, and make a mental note of some cue to know when to start the incoming track.
When the incoming song becomes outgoing, this stuff will matter.
(News at 11.)