Sweet Headache

What do DJs actually do?

In various discussions with non-DJs, I noticed a lack of understanding of what DJs actually do when they are spinning records. This can result in both a lack of respect for a DJ’s work as well as a certain mysticism around DJs.

So for all of you who ever wondered about this, here’s a little explanation of what the people at the decks actually do. I will concentrate on electronic music DJing here, but some things can be generalized to other genres. However, blending tracks into one another so that it’s hard to tell where one track ends and the next one begins is a quality that is valued more in electronic music than in other genres.

Beatmatching

Beatmatching can be considered as the core skill that any electronic music DJ has to master. The underlying principle is quite simple: Every track runs at its own speed, so if you want to mix two tracks seamlessly, you have to make sure they are running at the same speed.

You normally do that by using the pitch slider that every DJ turntable or CD-player has. This slider does nothing more than make the track play a little faster or slower.

The speed of a track is usually measured in beats per minute (BPM). Let’s assume we have track A at 130 BPM and track B at 125 BPM and you want to play track A first and then mix track B into it. That means you have to change the speed of track B by +4% so that both tracks run at the same speed.

Once both tracks have the same tempo, you also have to synchronize their rhythms. In electronic dance music, rhythms are usually based on a 4-beat measure. That means that elements are usually repeating after a number of beats that can be divided by 4. In order to have two tracks run synchronously, you have to start the track B so that it starts precisely at the beginning of the rhythmic pattern of track A.

A DJ software such as Traktor or Cue can help with this process, but many DJs still find it important to be able to do this by hand.

Fading and Equalizing

DJs typically use a mixing console that allows them to pre-listen to the next track while the current track is still playing through the main audio system. This also facilitates beatmatching as it is quite hard to sync two tracks without being able to listen to both at the same time.

Once both tracks are beatmatched, the DJ can simply use his mixing console to fade out the current track and fade in the new track. The simplest way to do this is to use the so-called Crossfader that automatically reduces the volume of one track while increasing the volume of another.

However, many DJs like to use the equalizer to make their mixing even smoother. The equalizer is used to emphasize or de-emphasize various frequencies of a particular track.

Example: If you emphasize the lower frequencies of a track, the bass becomes louder. If you emphasize the higher frequencies of a track, the hi-hats or vocals become more dominant.

By using the equalizer to emphasize or de-emphasize certain parts of a track, they can make the transition between two tracks very smooth.

Is that it?

These techniques are usually considered the basics of electronic music DJing. Beatmatching, fading and using the equalizer are usually the biggest part of a DJ’s performance. The theory behind those two techniques is not that hard, but it usually takes aspiring DJs a few weeks or months to master these.

However, a big part of being a good DJ is about having a good library of tracks to play. DJs often spend a considerable amount of time and money to build their library and to find tracks they (and their audience) like.

The order in which tracks are played also makes a big difference. Some tracks sound especially good when played after each other while some tracks don’t match well even though they are running at similar speeds. Many DJs also find it important to have a certain dynamic component in their set and  - for example – start with rather smooth tracks and work track by track towards music with a higher energy level.

I am just telling you all this to make you understand that the basic skills necessary to become a DJ are not magic at all. DJing is mostly a skillset that can be taught, understood, practiced and mastered. There is no big difference between what your local club DJ does and what a superstar DJ does when they are performing behind the decks.

I will write a bit more about what makes a famous DJ famous in a future blog post.

Image: http://www.flickr.com/photos/smeerch/225107882/ // CC-by-nc-sa