in this article, i will try to explain why a DJ needs to pay attention to beats and bars, what beats and bars are to begin with, and how to make transitions sound better by paying attention to the internal structure of the tracks. it's a long read, but it's a step by step guide, so should be easy to follow.
non-djs may also find it interesting if they're curious about what building blocks trance tracks are made of.
this is an aspect of DJ mixing that apparently many beginning DJs have problems with (especially in the software mixing world). the source of the problem is that many genres of EDM, including trance, techno and house, have a certain structure in their tracks. this structure is universal, any and all tracks adhere to it strictly. (there are rare exceptions, where a track jumps out of that structure at some point, but overall it still adheres to the structure.)
and why does a dj want to care about this structure? the thing is that this structure isn't just a theoretical thing, but you can actually hear it. this structure tells the producer where a break starts, where a break ends, where to put repeats and loops of some parts of the track etc. once you figured it out, you can easily hear it, and you will be able to hear it in all tracks the same. when doing a transition, a dj wants to align both tracks to the same structure, so both tracks will have the same overall sounds at the same time, making for a nicer blend of tracks.
don't worry if you don't understand what i'm talking about yet, you will (hopefully) when you finished reading this.
let's get started by explaining what a beat is.
load up a track in your favorite player, or vdj or whatever, and start playing it. listen up to the point where the bass kick (that's the strong "boom") hits for the first time. some tracks start with the bass kick right off the bat, others will have an intro part and will hit the bass kick a bit later.
basically, the bass kick is one beat. every time you hear the "boom", it's one beat. note that even if the parts where the bass kick stops, such as in the break, the beat still goes on, even if you can't hear it. it goes on throughout the track, bass kick or not.
now it's time to do some counting. start playing your track, and when it comes to the first bass kick, the first boom, the first beat, say out loud "one". it really has to be the very first beat in the track, if you missed it, don't just skip over it and put the "one" on the next one, instead start over until you get it. once you got the "one", keep listening, the next beat will come right after, and you say out loud "two" on this beat. so you got two beats down, let's continue this for two more beats, on which you say "three" and "four". you can stop counting after this.
so, in other words, while you hear "boom boom boom boom" from the track, you will say out loud "one two three four", at exactly the same time, in exactly the same speed.
you've just found yourself a bar. that's right, four beats makes up one bar. or in other words, "one two three four" is one bar, which is the same as saying "boom boom boom boom" is one bar.
now keep listening to your track and keep counting. but don't continue counting up from four, don't continue up to five, instead repeat the 4 beats from the bar. so while you're listening to the track, you will be saying "one two three four one two three four one two three four one two three four" over and over again, always on the beats. by this, you're keeping in beat with the lowest level of the musical structure, known as 4/4 time signature, meaning there's 4 beats in a bar.
now that we know what a bar is, we can move up to the next level of structure in a trance tracks. bars come in groups. in order to figure out where those groups are, we have to count the bars. and in order to count the bars, you can do the following.
start playing your track once again and count the beats again. while going "one two three four one two three four ...", emphasize the "one". say it out louder, and say the "two three four" less loud. continue this for a while.
the next step will be not saying the "two three four" at all any more. keep counting as before in your mind, but say out loud only the "one". continue this until you get a feel for where the "one" is. also listen carefully to the track, the "one" has a distinct sound, you should be able to recognize it even if you seek to a different part of the track and haven't been counting since the beginning. the "one" always sounds the same.
so if you're doing it right, you will be saying out loud "one ... ... ... one ... ... ... one ... ... ... one ... .... ..." now. the "two three four" will still be there, but only in your mind, you won't be saying them now. try to get to a point where you're actually only paying attention to the "ones", completely ignoring the twos, threes and fours, not counting them in your mind either. so in other words, you will say "one", then three beats will pass by, then you will say "one" again and so on.
now for the big challenge: instead of just saying "one" all the time, you need to count the "ones" now. so instead of going "one ... ... ... one ... ... ... one ... ... ... one ... .... ..." as before, you should go "one ... ... ... two ... ... ... three ... ... ..." and so on. in other words, you will say "one" on the first beat, then three beats will pass by, then you will say "two", then three more beats will pass by, then you will say "three" and so on.
if you're having difficulties with this, try counting the beats like this: "ONE one two three TWO one two three THREE one two three" and so on.
once you've figured this out, start playing your track again and do the counting. count the bars (NOT the beats) and count no further than eight. in other words, going by the beats, you should be counting like this: "1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x" and then STOP (with the "x" denoting a beat that passes by without you saying anything).
if you got that far, you successfully counted through a group of 8 bars. in EDM, a group of 4 bars is called a "phrase", and in trance you will (almost) always have groups of 2 phrases (with the second being a repeat or variation of the first), giving you groups of 8 bars. this is the most basic building block of a trance track. it takes roughly 15 seconds for 8 bars to pass by (14.2 seconds at 135 bpm, 13.7 seconds at 140 bpm).
now going back to the counting: play your track again and do the counting as before, but don't stop after 8. instead, at the point where you would move on to count the "9", start over at 1. if you're doing it right, your counting will be like this:
"1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x 1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x 1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x 1 x x x 2 x x x 3 x x x 4 x x x 5 x x x 6 x x x 7 x x x 8 x x x ..." (if it's easier for you, you can also count "1 2 3" instead of "x x x", so you'd be going like "1 1 2 3 2 1 2 3 3 1 2 3 ...".)
by now you're probably curious what good this is supposed to be. start over with the track again and start over with the counting too. pay close attention to the track and which number you're on. if you're doing it right, you will hear something in the track changing exactly every time you say "one", that is, at the beginning of each group of eight. maybe a hihat will come in, maybe some synths will come in, maybe the track hits the break, something like that. also, at the end of each group of eight, that is in the 8th bar or at the end of the 8th bar, always just before the next "one" hits, there is usually something like a small "break", with the bass kick stopping for a few beats. pay close attention while listening, you'll hear it. this is what you need to get a feel for, from that you will hear when the next group of 8 bars is starting just by listening to a track, even without counting anything.
now how does this come into play with mixing? easy enough: when doing a transition, you need to make sure that the "1" bar of the incoming track will sit exactly where the "1" bar of the outgoing track is. imagine you're preparing for a transition and there's a guy sitting next to you, doing the "1 x x x 2 x x x 3 x x x ..." counting for the currently playing track. now you start playing the next track that you want to mix in, imagine there's another guy sitting there, doing the same counting for the new track. your goal is that both are counting the same numbers at the same time, that is both should be saying "1" at the same time, and "2" at the same time and so on. if you manage to do that, the transition will be much nicer sounding, and you will also be able to do things like cut the bass (which you will always do at the moment one group of 8 is ending and when the next one is starting) without it sounding weird.
or in other words: the goal is that when listening to the finished set, or the finished transition, you can do the bar counting (1 to 8 and then starting over again) throughout the transitions, with the grouping being valid after the transition as well. try listening to some sets and counting the bars while listening, you will notice the difference. and yes, the groups of 8 is valid also throughout breaks. it will be harder to actually count the bars, as there are no beats to hear, but any break's length will still always be a multiple of 8 bars.
hopefully i managed to confused the heck out of everyone who read this