More about different kinds of electrified musical instruments
Classical musicians are often dazzled and confused by the variety of electronic or digital musical instruments. While they all operate on electricity and sounds come through loudspeakers, there are subtle distinctions between the different types. Mainly, they differ by how they convert the human input into sound.
There are academic discussions on the definition of electrophones¹. Yet, here is a quick way to tell apart some common instruments that we usually encounter, from how sound is generated.
- Amplified vibration with electronics
- Sound from signal generators or sound banks
- Sound from computers or sound modules, driven by controllers
Amplified electronics
Electric guitars and bass guitars are likely the most common electric instruments. Sometimes considered chordophones, the strings are vibrated in ways almost identical to acoustic guitars or double basses.
The mechanic vibration is converted into electric signal with a pickup. The signal then can be amplified with different kinds of amplifiers, and be output to loudspeakers. Musicians work a lot on finding the good pickups and other electronics en route!
There are also traditional string instruments electrified, getting rid of the soundbox. When the strings are played, the vibrations go through the bridge to the pickup. That’s why they are in all those weird hollow shapes, usually serving to avoid changing the musician’s posture. The sound quality now depends heavily on the quality of the pickup, since the vibration conversion would be quite dramatically amplified.
Analog synthesizers
Sounds can be directly generated with electronics without real vibrations. Again, we just need some pulses of strong and weak voltages, with certain frequencies, to drive the loudspeakers. The theremin is one legacy in the family of pure electronic instruments, having an age of 100 years!
Oscillators are some simple electronics to produce a periodic signal. Sine waves can easily be generated with sinusoidal oscillators, and other basic waveforms can also be created by combining sine waves!
Most analog synthesizers allow basic waveform generation with oscillators. There are often further electronics for controlling the gain, or routing through filters, creating signature sounds of electronics. Usually there is also a keyboard interface to decide the frequency to play (or, to generate a sound).
Soon people found that reconfiguring through circuits got too complex and time consuming, and started to store sound patterns into sound banks for playing back. There we have simple electronic pianos having all sorts of musical instrument sounds!
Digital instruments
Computer memory has a trend to get half cheaper every 18 months (a.k.a. Moore’s Law). Eventually sounds of not just various instruments, but more of different dynamics, articulations, bowing/playing methods, can be easily stored for manipulation with more powerful chips.
New methods of sound synthesis no longer depends on real oscillators and electronics (yet we can still simulate the vintage electronics with software), but more on computations. Play the note head from this file, going with note sustain from elsewhere, and the end perhaps with a fade out. Lots of new possibilities come true with computer software.
People now work harder with new ways of controlling music. New piano keyboards, mallet percussion pads, drums, winds, and even new shapes of unimagined ways of making music. It’s not too weird to see a musician making sounds of violin or timpani with a saxophone-shape controller!
Many of digital instruments and controllers rely on the king of digital music — MIDI! Just note on/off, pitch, velocity, with a large set of control change (CC) messages are already pretty good for musical expressions. Best thing with this veteran is the high compatibility and extensibility with hardware and software systems.
But certainly, no artists are to be bounded by standards. The NIME conference every year show cases a lot of new possibilities of music and machine interacting with each other. After all, only the sky is the limit for new ways to create new art…
[1] Britannica: electrophone https://www.britannica.com/art/electrophone
