This Section is a free beginners DJ course for music mixing. You will learn the basics of the professional mixing technique used by DJs all over the world. You will learn how DJs mix songs in night clubs. We are not talking about radio station mixes.
At the end of this course, you'll be able to perfectly mix 2 songs together seamlessly like a professional DJ does. Of course you need to practice a lot before you can go and mix in a night club. But all the basics you need are in the following pages.
The course is divided into 6 sections covering the mixing technique:The DJ minimal equipment or software A typical song anatomy Mixing basics CUE points BPM and pitch control Putting it all together Read this course a first time in 15 minutes to get a global view of all the terms used. Then read it again slowly and take your time to practice. The Key for success is practice!
First of all, in order to mix 2 songs you need 2 audio sources. Most of the time, DJs use a pair of Turn tables or a double deck CD Player. Recently, new Software was introduced to the market of DJ tools featuring double deck MP3 players. DJ players are designed specially for mixing. They should have at least the possibility to modify the playing speed of the song (known as pitch control) and pausing the tracks at a precise point of time (known as CUE points).
Next, you need an audio mixer. This can be a real mixer console or a virtual Software mixer. The mixer is the central part of the whole DJ system and it is where the songs get really mixed together.At last, you need an amplifier with speakers and a head phones.
If you are a starting DJ and don't want to invest in heavy professional equipment, you can use your computer instead. It's really all you need to get started along with some good software. you can buy software for less than 200$ including a double deck MP3 player with an embedded virtual mixer and other functions like pitch control and CUE point.
How to cable the DJ system if you're not using your computer: -hook the output of player A to the input 1 of the mixer (or line 1)
-hook the output of player B to the input 2 of the mixer (or line 2)
-hook the output of the mixer to the input of the amplifier (usually this is called AUX for auxiliary)
-hook your head phones to the mixer
You can also use your computer with an external mixer. Specially if you have a sound card with 4 outputs. Most recent sound card have this feature. Or, you can install 2 sound cards on your PC.
99% of the songs follow the same structure. A song starts with an intro and ends with an Exit. Theese are sections where only drum beats and music goes on without lyrics. This is usually the playground of the DJ. This is where all the mixing happens.
Here is what a song looks like:
I = Intro
V1, V2 = Verse
R = Refrein
S = Solo
E = Exit DJs measure the length of each section with the number of drum beats. The following thumb rule apply for most of the songs. Try to count the beats for each section and in group of four beats: 1-2-3-4...1-2-3-4...1-2-3-4...1-2-3-4
usually the length of the intro, refreins, solo and exit is 32 beats each (that's 8 times the 1-2-3-4 counting). Verses are 64 beats each. Sometimes the intro is 2 x 32 or 3 x 32. In all cases it is a multiple of 32. There are also some exceptions like having parts of 16 beats between the refrein and the second verse.Songs are called tracks when loaded in double-deck players.
The basic idea is to start track 2 before the end of track 1 that is currently playing. The problem for the DJ is to exactly synchronise the start of track 2 with the end of track 1. This shows the importence of understanding the song anatomy. We saw that the intro of track 2 lasts 32 beats. On the other hand, the exit of track 1 also lasts 32 beats. So ideally, we need to match beat 1 of the exit of track 1 with beat 1 of the intro of track 2.This figure shows the perfect mix:
Graduation shows the beats
For this we will face 2 dificulties:
-Adjust track 2 so it starts exactly on beat 1 when we press the play button. This step is called the CUE
positionning and is prepared in the head phones while track 1 is still playing.
-Adjust the speed of track 2: Lets suppose that track 2 was precisely started on the beat 1 of track 1's exit. If the speed - or tempo - of track 1 is faster then track 2, track 1 will reach the end before track 2 finishes its intro. So you have to synchronize the tempo of the tracks and this is called synchronysing the BPM (beat per minute)
In order to start track 2 at the desired time (beat 1 of track 1) and to match the first beat, track 2 should be placed on pause and be ready to start instantly.
On a turn table, listen to track 2 from the start and wait for the first beat. Then hold the vinyl disk on the edge. The turn table should keep turning underneath (use a special tissue called a slipmat between the turn table and the vinyl to reduce friction). You can also slightly forward or rewind the vinyl to place the needle on the start of beat1. When track 1 enters the exit, release track2 and the beats should match. This requires some training at the beginning then it becomes more natural.
On a double deck CD or an MP3 software, listen to track 2 from the start and press the CUE button when you hear beat 1. The player then enters CUE mode. Meaning it pauses the track and repeats the last second of music in an endless loop to show you the exact position of the CUE. You can then go forward or rewind with high precision using the Jog (little wheel). The Jog will let you precisely position your CUE point at the beginning of beat 1. Some professional Players have auto CUE so they automatically find the first beat for you and get paused on it. Others memorize the CUE point you set so when you use the same Track, the CUE point is automatically selected. Some also memorize more than one CUE point for each song. Finally, when track 1 enters its exit, release track 2 and the beats should match.
This figure shows the exact place where the CUE point needs to be placed on track 2:

The next step is to adjust the speed so the beats of track 1 and track 2 match all the way.
BPM definition: it's the number of beats per minute. The BPM represents the tempo of a song. In other words its speed. In general for disco, dance and techno, the BPM is between 110 to 150. So Trance has a higher BPM than House or disco; and house has a higher BPM than Hip-Hop.
Once both tracks are playing, and the first beats are synchronized, the speed of track 2 should be adjusted to keep this synchro. In fact, it is uncommon to have exactly the same BPM for both tracks. On professional equipment, the DJ can get an automatic extraction of BPM displayed on screen. The BPM can then be saved in the memory of the player. Some software let you tap along with the beats and calculate the BPM for you. But this is very slow and unreliable.
Having the BPM displayed is not mandatory. In fact professional DJs don't use it. They prefer to do the mix on the fly. This is why it is not available on turn tables.
The idea is to have the same BPM for both songs before raising the volume of track 2. So if the beats of track 2 are in advance, you should slow down track 2 and if they are comming late, you should accelerate it.
This example shows the case where track 2 is too slow. It should be accelerated so it can catch up track 1. If not, track 1 will reach the end before the beginning of track 2's first Verse:

Slowing down or accelerating is done using the Pitch control slider. In general, you can adjust the pitch by more or less 12%. Values above 12% should be avoided as they badly mess up the song.
The pitch should be modified very slowly and very progressively if the volume is up. If not, you'll have noise deformations as in old tapes left under the sun!
Sometimes the BPM are equal but there is a slight delay between the beats of track 1 and track 2. In this case it is practical to use the pitch bend buttons (+ and -) to temporarly accelerate or decelerate the pitch without modifying the BPM synchro as long as you are pressing on the buttons. When you release the button, the pitch gets its previous value. The Pitch bend are not available on all systems. This enables you to accelerate or slow down the pitch without loosing the synchro.
Adjusting the pitch is definetly the most diffcult part of the mix. Once you get successeful at this, you can start mixing mix almost any kind of music.
bron: MP3-Mixer.com