What exactly is 8-bit sound?

I love 8-bit music. The cheerful melodies and unique sound of Super Mario Bros. and the like have burned themselves into my long-term memory. The simple computer noises and their sing-song melodies spark vivid childhood memories for me.

8-bit music is still made today. I’d say even more than ever before, given the popularity of remakes of old hits. The YouTube channel 8 Bit Universe boasts a treasure trove, from Michael Jackson to Queen to Gorillaz.

8 bits = 256 values

But what exactly is 8-bit music? There’s no clear answer – although 8 bits are clearly defined. 8 bits mean that 2 to the power of 8 – or 256 – different values are possible. For example, an 8-bit graphic has 256 shades per colour channel.

Does that mean that 8-bit music can have 256 different pitches? Not necessarily. It depends on the device. The same applies to the length of the tone or the volume. Unlike graphics, there’s no clear connection between the name 8-bit and the number 256 when it comes to sound.

There are also 1-bit graphics, 10-bit monitors and 16-bit photos, where it’s always about the number of colours that can be displayed simultaneously. In music, in contrast, there are only 8 bits. Unless you’ve ever heard of 10-bit music?

The only thing that can be 8-bit in audio is the bit depth. However, this has nothing to do with 8-bit music. No sampling is used for the music in old video games; the computer chip generates the sounds itself. That’s why 8-bit tracks are also referred to as chip tunes.

What does «8-bit» refer to?

The term doesn’t refer to an audio property, but to the processor architecture. So, 8-bit music is music created by an 8-bit computer. Or music that can at least can be played on one.

The Commodore 64 and Nintendo NES game consoles have processors like these, for example. The latter’s successor, the SNES, works with 16 bits, as do the Commodore Amiga and early DOS computers.

The problem with this is that processor architecture doesn’t give much of an indication about a device’s audio capabilities. Many 8-bit computers can only emit a simple beep, if that. At the other end of the spectrum is the Commodore 64, which has its own powerful sound chip for the time: the MOS Technology SID.

This offers similar possibilities to a polyphonic analogue synthesizer. It can only play three voices at the same time, which puts it behind the NES. The timbre of the three voices can be designed in a variety of ways. There are five channels on the NES, but their timbres are fixed. And only three of them can play melodies at all. Because the C64 can change the sound of a voice in the middle of a track, you can play a lot more than three instruments, albeit not at the same time.

Fake and true 8-bit

8-bit music isn’t usually created on an 8-bit computer nowadays. Many of these tracks can’t be played on an 8-bit computer. They only can if the musician has made it for that purpose. Otherwise, pieces of music created with today’s tools are too complex for 8-bit systems, such as when chords are used. This exceeds the limit of three voices. Any 8-bit system would also be overwhelmed with sound effects such as reverb or echo.

Today, 8-bit sound can be used alongside acoustic instruments or modern synthesizers. In this context, 8-bit is more of an instrument than a specific type of music.

The term «true 8-bit» is sometimes used to differentiate from music, such as in the video above. It’s not entirely clear what that means either. As I understand it, it means chiptunes that could theoretically be played by an 8-bit system. Although this excludes mixed pieces and obviously tracks that are too complex, it’s still vague. Because, as I said earlier, every 8-bit system has its own idiosyncrasies. Also, being limited to three voices doesn’t mean the piece can be played by a C64 – far from it. It has to be turned into a format that the computer can understand.

A style of music with typical characteristics

Does this mean that the term 8-bit music is meaningless? No. Because, despite their major differences, the sounds of 8-bit devices also have things in common. The most important thing is that no saved recordings are played, unlike on later computers; the processor generates the sounds.

The typical sound of old video games comes from the fact that simple sound waves are what’s generated, such as with an old synthesizer. Each waveform sounds slightly different, with triangle, sawtooth, square, and pulse waveforms common examples. The latter is a shortened square. Noise can also be played, which is important for drum effects.

This makes sounds that arise from these simple waveforms characteristic of 8-bit music. In the purist variant, i.e. «true 8-bit», these sounds are all there are. That means no vocals, no realistic instrument sounds and no modern synthesizer effects.

The second most important stylistic feature is the frequent use of arpeggios, or arps for short. An arpeggio is a chord whose notes are played one after the other rather than simultaneously. A good example is Johann Sebastian Bach’s Prelude in C Major – which is practically just arpeggios – here in an 8-bit version.

Even expensive synthesizers could only play one note at a time in the 70s. Originally, arps in electronic music were a trick to circumvent the limitations of polyphony. However, the rapid succession of individual tones developed into a stylistic device in electronic music and is also used when it’s not technically necessary. The automatic playback of the same note in different octaves is often referred to as an arp.

To create the gurgling sound familiar in old video games, arpeggios are played very quickly. Here’s an example from the Korg Gadget iPad app with octave arpeggios.

8-bit music works with any genre of music, but certain genres are more appropriate than others. In principle, hip-hop and spherical music only work in a mix with non-chip sounds. Baroque music is very suitable, as shown in the Bach example above. Funky pieces also work well, because the tones are often not played simultaneously, but rhythmically offset.

8-bit is a style, not a technical feature

The term 8-bit music describes a specific aesthetic rather than a technical process. It’s a style. It’s about reproducing the typical sound of a certain time – and sometimes creatively mixing it with other musical elements.

The fact that the sounds are produced very differently today than in the 80s may be technically interesting, but it doesn’t matter in terms of emotion. I’m even more moved by the modern mixes than the original video game sounds.