MIDI is the ubiquitous protocol which most music machinery uses for communication. It stands for Musical Instrument Digital Interface, and it's a simple protocol which can only transmit very limited data. It replaced CV, which stands for Control Voltage. CV is more expressive than MIDI, but its original implementations were very unreliable and inconvenient. MIDI offered reliability, regularity, perfect timing, and rock-solid stability.
For years, a small group of hipsters and hackers have wanted to replace MIDI with OSC, which stands for Open Sound Control, but it's never really taken off. The protocol carries more data than MIDI, uses a URL-like naming scheme, and has a number of other significant advantages, but has failed to see much acceptance, enthusiasm, or awareness. My gut feeling is that it was just too complicated.
Meanwhile, CV's experienced an incredible renaissance. Where previous decades saw a great deal of incompatibile implementations, most CV-oriented gear today organizes around a common standard called Eurorack for voltages, machine sizes, and power consumption. Artists such as the Chemical Brothers, deadmau5, John Tejada, Orbital, Richard Devine, Nectarios, and Alessandro Cortini from Nine Inch Nails have embraced Eurorack, and Eurorack manufacturers have produced a ton of expressive, very powerful, and wildly innovative new instruments. Most Eurorack manufacturers are tiny companies — one of the best, Cwejman, is literally one person — but bigger names like Roland and Dave Smith Instruments have gotten involved in the past few months.
I'm not entirely sure what the lesson to learn here is. CV's renaissance stems from several factors:
- Control voltage is an intensely simple API. (Control voltage is to synths what
stdoutare to Unix.)
- Electronics are more reliable to manufacture today than they were when CV was first developed.
- Vintage synth fanatics kept CV alive.
- Advances in DSP and ever-tinier microprocessors make it easier than ever to build tiny, sophisticated instruments.
- Software-emulated modular synthesis systems like Reason and Reaktor introduced a new generation to modular techniques.
- Eurorack modules interact very simply and readily, while the Eurorack market is full of quirky experiments and ideas, sold in short runs. This combines intermittent rewards with scarcity, so it's a lot like if Lego blocks were sold the way Magic: The Gathering cards are. That's inherently addictive, and it's caused the market to grow.