Friday, March 29, 2013

Flying by Wire

My father-in-law is a pilot and some years ago told me about the transition on airplanes from traditional "mechanical" style of flying to the newer "fly by wire". Basically, the old electric, servo-motor, pneumatic type controls were replaced by embedded computers (I'm oversimplifying). What this meant was that instead of sending electric impulses that directly controlled motors, flaps, etc, binary messages were sent to embedded controllers that would in turn, control the motors, flaps etc.

This would allow for "manipulation" of the pilot's action where the embedded device had a "better idea" (he was not a fan!). So a violent movement on the controls might be changed to a less violent movement that would prevent the plane from stalling - or at least that is the general idea. So instead of relying on Sam the mechanic who has a nice greasy shirt, cool pin-up calendars and a beard, you are relying on Simon the programmer who plays fantasy games and always smells a little like cheese. Quite a transition!

The reason I bring that up is I do quite a bit of music making with traditional sounding tracks (saxophone, trumpet, bass, guitar) and yet I don't even have a microphone in my studio. Instead of passing analog waveforms electronically into my music, I tend to send binary messages that the computer then takes up and uses to create noise. Seems to be a very good analogy.

In the case of MIDI keyboards, this is pretty common. Whatever you are doing on the keyboard is being encoded into numeric messages that are passed via MIDI cables, or USB cables into a computer that then passes the events into software that is creating sounds, applying effects and ultimately making noise.

A good friend of mine, Marty, uses a much more complicated method of soundmaking. He starts with a manual exciter which creates oscillating vibrations, these go through an echo chamber made of shaped wood which modulates the waveforms projecting them out of a round hole into an irregularly shaped rectangular space filled with other shapes that affect the waveforms. Some of the randomly bouncing waveforms are "captured" by a membrane that vibrates in time with the excitations in the room, produces an electronic signal that is ultimately transformed from analog to digital format and stored in a file. Because I find this entire process mind-boggling, I tend to stick to the simple MIDI method myself.

In the case of trumpets or saxes, I like to use a wind controller which is "played" like a traditional instrument with keys to finger, a mouthpiece to blow into and, of course, a USB cable coming out the other end. The fingerings change internal note numbers, the breath controls a pressure monitor that also sends numeric impulses continually via MIDI. A few other sensors allow me to send modulations as well such as a thumb control to "bend" the note or create a "growl" sound (these are configurable). All in all, this is much simpler to me than analog!

Like the airplane, the receiving computer can "manipulate" the raw data I send it. It can use any program it has to create the sound. So, with the same inputs, it can produce saxophone sounds, trumpet sounds or entirely electronic or digital synth sounds. The possibilities are endless using just one input device. As time continues and software develops, even "analog" sounds can be modeled effectively to where even if not perfect, they are hard to distinguish from physical instruments.

I suppose I'm just rambling, but technology always fascinates me and usually delights me! Maybe I should grab a beer with Simon the cheesy computer guy.

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