This is a guest post by Leonard J. Paul, a composer, sound designer and educator who first got his start working on Sega Genesis back in the ’90s. You can reach him at the School of Video Game Audio (SoVGA.com) or on Twitter @VideoGameAudio at any time.
In this four-part article series I’ll be going through my sound design process of creating retro game sound effects using digital audio tools called trackers. Frequency modulation (FM) synthesis, pattern matrixes, algorithms and hexadecimal numbers might seem strange at first but I hope that beginning sound designers as well as pros can pick up a few helpful sound design tricks in this tutorial series.
Here’s an overview of the article series:
- Introduction to Trackers and the Genesis: What a tracker is, why you would use a tracker for sound design, an overview of the audio capabilities of the Sega Genesis (also known as the Sega Mega Drive) video game console, and some examples
- Basic Synthesis: How trackers influence working with synthesis, examples of synthesis using the square waves and noise channel on the Genesis, basic tracker commands, and how to make some interesting sounds using the DefleMask music tracker
- FM Synthesis: What FM synthesis is, how it is implemented on the Genesis, what sounds it is good at making, and unique sound effect examples of Genesis FM synthesis
- The Full Mix: How to combine sample, square, noise, and FM channels together into a complete sound, plus thoughts on using similar techniques in the future
We’ll be looking at how the Sega Genesis creates audio as the concepts that you learn here can be applied to many other classic game systems, including the Nintendo Entertainment System (NES), Nintendo Game Boy, and the Commodore 64. I’ll take you through the steps of creating sounds for the Sega Genesis, a console that includes basic square and noise waveforms, FM synthesis, and sample playback.
Let’s get a quick start on how Genesis music and sound effects might sound like using DefleMask:
- Download and install Deflemask for your PC, Mac or Linux system from DefleMask.com
- Open the Genesis demo song from Sonic using the menu File → Open… and open the file Deflemask\songs\modules\Genesis\Demo Songs\sonic_greenhillzone.dmf
- It should start playing right away, enjoy the Sonic the Hedgehog vibes! :)
- Download a work in progress of mine for a “crying” sound effect from here (right-click to “save as”) and open it using File → Open… as well
Deflemask is just one of a long line of music trackers. Trackers first got their start back in 1987 on the Commodore Amiga with a program called Ultimate Soundtracker by Karsten Obarski. The Amiga had four channels of sampled sound and a tracker was a way to balance the capabilities of the hardware with the needs of the composer. One of the main differences you might notice between trackers and a regular DAW in the video below is that time flows in a weird direction. This allows us to easily give extra information on how to modulate a sound after it is played in each of the vertical columns as they relate to the four channels. This will be similar to Deflemask except that we have ten channels to work with. It’s also oriented this way as the graphics resolution of the Amiga was relatively low and so using text was a way to store information for the sound channels in a compact way. We’ll look into the details of trackers even more as we continue to work with DefleMask in the upcoming articles.
Since then there have been many different types of trackers. Make sure to check out an impressive chart of the growing list of trackers through history at the Tracker History Graphing Project. Some of the more popular trackers include OpenMPT for the PC, Famitracker for making NES songs, LSDJ for Game Boy and Deflemask for various classic console systems (including the Genesis).
A lot of pros got their start in music using trackers and several artists still use it today to produce their music. These artists include Aphex Twin, Venetian Snares, Calvin Harris and others. Many popular chiptune artists such as Chibi-Tech, virt and Toriena use trackers in their current music production. There’s even options for using trackers with modern Eurorack modules, which shows that there’s a good interest in using trackers for audio these days. As a reference, I’ve put some together for you so that you can have a listen to how each artist used trackers in different ways in this YouTube playlist:
But why not just use your DAW with some retro console plugins to make sounds? This is a great way to make sounds quickly but I’ve found it didn’t push me into as many creative spaces as working with a tracker did. It’s like the difference between working with a chainsaw and a chisel, you’ll likely develop a deeper understanding with your materials when working slower and more hands-on, which opens up new creative possibilities along the way. If you’re looking to get the lush organic sound of an acoustic instrument quickly, then trackers likely aren’t your tool. Trackers have a character all their own, and I feel that they’re perfect for doing retro sound design.
There’s a several creative reasons to prefer using trackers over plugins that simulate a Genesis. One of the main reasons for me is that I’ve gotten used to the process of working with a tracker and it really helps me focus on all the different ways I can take advantage of all the ways that the sound can be modulated and not be distracted by other features available in my DAW. Each sound is both an artistic and logic puzzle that is fun to solve using the parameters available on the sound chips. I think the possibility of running the sound on the actual console itself is pretty fun and helps increase the nostalgic vibe in the design of the sound itself. Learning even a small amount about doing retro sound design this way can give you a lot more respect for game audio artists of the past and new ideas for the future.
The Sega Genesis was released in North America in 1989 and contained two sound chips. The main audio chip was the YM2612, which allowed for six channels of FM synthesis with the sixth channel having the option of being used for digitized sound. The SN76489 chip allows for four channels of sound set to square waves, with the option of the fourth channel to be used for noise. We’ll look at the audio hardware of the Genesis in future articles as we dive further into the details. In DefleMask, the six FM channels (FM1-6) are on the left with the remaining square wave channels (SN1-SN4) on the right. This will hopefully become more apparent by having a look at the DefleMask sound effect videos below.
Throughout this series we’ll explore how the brash style of the Genesis found a great fit with the sounds of FM synthesis and how we can use it in our own sound design. One video excerpt that gives great insight into music during the era of the Sega Genesis is in The making of Streets of Rage 2. This video gives us a better idea of the musical tastes of the time, how sound design and music needed to compete with each other over the polyphony of the sound chip and lots of other fun details about working with audio on the Sega Genesis.
Crying, Whistling and Shooting
Here’s a few example works in progress that show some different ways that I’m designing sounds for Shakedown: Hawaii using the Sega Genesis format in DefleMask.
A quick overview is:
- Crying – Shows how we can make a vocal sound just using a single FM channel with some pitch bends
- Whistling – Demonstrates modulating both the pitch and volume envelope with a bit of breath at the start to make a whistling sound
- Shooting – Gives an example of how we can add synthesis layers to sampled sound to add extra frequencies and impact
I started learning how to use trackers seriously in 2008 when starting sound design work on Retro City Rampage. I learned the OpenMPT tracker using the Impulse Tracker format with a set of samples meant to replicate the sound of the NES using songs available from the chiptune artist virt (Jake Kaufmann). I found that I enjoyed making sound effects with the system so much that I wanted to create some songs for the game along with other two composers virt and Norrin Radd (Matt Creamer).
In 2015, I started working on the follow up to RCR called Shakedown: Hawaii. This game pushes the graphics style into the 16-bit world of the Sega Genesis and similar consoles of the early 1990s, so I decided to work with the Genesis sound as a basis for my sound design. One of the key advantages to working with trackers and games is the file size. Modern audio compression formats work well to 10:1 but trackers allow your audio to many times smaller. RCR on the Nintendo Switch was 24 MB and had over 2 hours of music as well as hundreds of sound effects due to using a tracker format. Getting a smaller download size can be key for mobile, portable and web games.
Usually composers would also do the sound effects for classic consoles like the Genesis but they usually didn’t use trackers. The tool most commonly used for audio was GEMS (Genesis Editor for Music and Sound effects) used on over 200 games (such as Comix Zone, NBA Jam and Shaq-Fu) which allowed composers to hear what their MIDI compositions would sound like on the Genesis using special hardware and would compile their music and sound effects down to a size that would work on the console. Memory was very expensive and the cartridges for the Genesis were usually less than 4 MB for the entire game which often meant around 100 KB for audio for all the note data, patch data and samples. The following video gives a good idea of how music was created using tools like GEMS in the mid-90s:
One of the more advanced features in GEMS was allowing it to communicate with the game so that you could trigger events in the game from the audio and also change the playback of the audio based on conditions in the game. Some composers were able to use custom sound drivers for their music and since each had different capabilities it changed the overall sound and approach, similar to using different DAWs. Tracker file formats are supported in FMOD Studio, Unity and other game development tools to help reduce the file size. In more complex implementations, trackers can be used to change the playback of the audio in response to the game, similar to the way GEMS did on the Genesis.
Donationware and Open-Source Music
All the tools used in this tutorial are available for free and although DefleMask is donationware so it’s good to contribute if you find it useful. There’s a great collection of free open-source tracker music that you can have a listen to from The Mod Archive, and you can play it online using Bassoon Tracker. If you like a song, you can easily find the details to download it and even remix it if you’d like. Without this open culture of sharing I wouldn’t have been able to learn how to make NES sound effects by using virt’s scores and my own path of creating retro sound effects and chiptunes would likely have been very different.
For the second article in our four-part series, we’ll start digging into making our own unique sounds with DefleMask and get a better idea about what all the numbers scrolling around the screen actually mean.