A music tracker is a piece of software with which you can create music, either by controlling the properties of a sound chip, or by playing pre-recorded audio samples. Trackers have a long history dating back to the 80s. Since then they have been used for video games, demos and music projects. Songs are saved to so called modules. They contain all the song data, including the samples, and are very small in size, compared to WAV files or MP3s. This makes them perfect for sharing music as well as learning the techniques of other musicians.
If you have never seen a tracker before the first thing you should know is that the music does not progress from left to right but from top to bottom, almost like when you're playing Guitar Hero.
In every tracker you will find at least three editors:
The pattern editor is where you input the notes. It consists of a big grid that is separated into channels. Each channel is a voice. If you want to play multiple voices simultaneously, you have to use one channel per voice.
Each cell of the grid consists of 5 parts:
Which are entered as:
C-4 01 30 037 ^ ^ ^ ^ ^- Effect | | | '- Volume | | '- Instrument | '- Octave '- Note
There are many different effects like volume and pitch slides, arpeggiation, vibrato, tremolo, and others. The effects may differ depending on the tracker. It is easiest to have the manual of your tracker open so that you can reference the effects at any time.
With sample-based trackers you are usually required to write the effect in each line at which it should be applied to the instrument or channel. Chip-based trackers on the other hand are typically state based. This means that you set the effect once, and it is applied to the instrument or channel until you explicitly stop or change it.
Once you have created the patterns in the pattern editor, you arrange them in the song editor.
There are two types of song editors. One lets you set a pattern for each individual channel. This lets you mix and match different patterns depending on your song structure. The other views the information of all channels as one pattern. This means that even if you have only small changes in one of the channels, you have to create a new version of the pattern.
With sample-based trackers, you create your instrument out of samples. There are trackers that allow you to use multiple samples for different ranges of the keyboard. The instrument editor is closely tied to the sample editor, which allows you to apply different functions on the samples like cut, trim, reverse, gain, filters, cross-fade, and others.
With chip-based trackers, the capabilities of the instrument editor depends on the capabilities of the chip. For instance, the SID chip that is in the Commodore 64 allows you to use different waveforms on the same channel. You can combine the waveforms to create instruments that imitate a snare or a drum. The SID chip also has the ability to apply filters and modulation to the voices.
Most trackers however allow you to create volume, pitch, panning, or duty cycle envelopes and macros.
An envelope is the change of a value over time. The most common way to model the audio properties of an instrument is by using the ADSR envelope (attack, decay, sustain, release). The attack and decay part are played when the key is pressed. The sustain value is held until the key is released. Once the key is released, the release part is played.
A macro is similar to a little program that defines value changes on a scale that is much finer than the lines on the pattern editor. How macros are written are very specific to the tracker that you are using.
Many trackers make use of the hexadecimal system which means that you don't count from 0 to 9 before carrying over the one, but from 0 to F.
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1A, 1B, 1C, 1D, 1E, 1F, 20, ... and so forth
Don't worry, most of the time you only need to know that the letters A to F are a part of the number.
AdlibTracker
Tracker for the Yamaha YMF262/OPL3 FM sound chip
DefleMask
Tracker for multiple different systems/chips, including Nintendo GameBoy, Nintendo NES, SEGA Master System, SEGA Genesis/Mega Drive, PC-Engine, Commodore 64, etc.
FamiTracker
Tracker for the Nintendo Entertainment System/Famicom sound chip 2A03
GoatTracker
Tracker for the Commodore 64 sound chip SID
MilkyTracker
Sample based tracker for XM modules
OpenMPT
Sample based tracker for IT, XM, MOD, S3M modules
SchismTracker
Sample based tracker for IT modules
Renoise
Sample based tracker with modern DAW capabilities
Besides the effects that your tracker comes equipped with, like pitch and volume slides, vibrato, arpeggiation, etc. you can also create more advanced effects.
Similar to envelopes, automation changes the audio properties of an instrument over a certain period of time. Different to envelopes, the automation is not bound to the instrument and the note on/note off events, but can span multiple notes and even patterns.
Volume automation can for instance be achieved by changing the note volume over time so that it increases or decreases. In most trackers there is a linear volume interpolation tool that generates the appropriate note volumes in between a selected volume range.
To make your beat a little more organic you can apply different volumes to your samples i.e. if you have high hats don't play them all at 100% but change it up a little by choosing a range you want the volume to be in and randomize the values.
Some trackers have randomization effects that can be applied to the instrument itself.
Ducking describes the effect when one instrument is lowered in volume when another instrument is played. For instance, whenever the kick drum is played, the bass or melody is lowered in volume, making place for the kick.
You can vary how much the volume of the instrument is lowered and how long it needs to recover to its initial volume. This can happen instantly, or following a linear or exponential curve.
You can achieve this by using volume automation on the instruments, as described a few paragraphs above.
You can emulate an echo or a delay by simply retriggering the instrument or sample. This is a very common technique. You can retrigger the sample with different volume, pitch and panning. The number of delays and the time between them can change. You can also vary the number of channels that you use for the delay.
The unison effect is achieved by playing the same waveform on multiple channels and detuning or slightly changing the pitch of each voice. This can be used for effect or to avoid situations in which similar waveforms cancel each other out.
An effect that is commonly seen in techno songs involves playing a sample of a very slow filter sweep with different samples offsets. This creates the illusion that the filter is modulated while the instrument is playing. Of course this can be applied to any kind of sweep.
A different form of modulation is the pulse width modulation. This is more typical for chiptunes. Instead of a regular square wave, some sound chips can output pulse waves whose width can be changed. Changing the pulse width over time creates the modulation effect.
Another effect that involves changing the sample offset is the time stretch. When you want to play back a sample at a lower speed, you could trigger it with a lower note. However, this also changes the frequency of the sample. If your pattern resolution is high enough, you can retrigger the sample with slowly increasing sample offsets. This will give the illusion that the sample is stretched without changing the frequency. Of course this effect has its limits.
To achieve a swing groove, you need to have a small delay in global song speed or tempo every few lines. If the tracker that you use does not have a groove setting, you can create a groove by switching between speeds or tempos in your song.
Typically you have one channel on which the global speed/tempo effect is applied throughout the entire song. How you apply the effect is up to your taste but it takes a little bit of experimentation to get it right.
There are some primitive filter effects that you can apply.
In chip-based trackers you can often manipulate the duty cycle of the pulse generators. This will give you different "colors" of a pulse wave, which makes for more interesting instruments. Some sound chips like the SID have built-in filter effects that you can program and automate.
In sample-based trackers, if there is not a built-in filter effect, you might be able to reduce the sample rate of the recorded audio. Besides degrading the quality of the audio material, it will also act as a low-pass filter, giving you a nice muffled sound.
Of course you can always use a program like Audacity to edit your samples.
This is a collection of other sources related to tracking