If this was all the Motor Synth did, it would still be pretty impressive -- if a bit one dimensional. Gamechanger has another trick up its sleeve though: reflective discs that sit on top of each motor. Those discs have patterns painted on them, and as they spin under a light inside, the black markings also absorb heat. The unpainted sections reflect that heat back to a set of infrared sensors. That data is then converted into audio signals -- either sine, saw or square waves. They sound much closer to a traditional analog synth but still have a character all of their own.
One of the best parts is that you get to see all of this happening, because there's a window you can view the eight motors through. You can actually watch as they spin up and slow down in response to your playing. Best of all, they're bathed in an appropriately angry-looking red light.
Beyond this, things start to look much more like a traditional synthesizer -- and that's not a bad thing. Because when you're starting off with an idea this bizarre, you need something to help ground it in the familiar. There's a standard ADSR (attack, decay, sustain, release) envelope, a multi-mode resonant filter (which can be bypassed), a drive circuit for adding distortion and a mod section that can add tremolo or vibrato or even affect the filter envelope.
The only control here you won't see on other synths is the accelerate knob (which doubles as a brake). This changes how quickly the motors get up to speed and how quickly they come back down. It might sound slightly odd, but it's essentially a glide control.
There are a number of different connectivity options too. There are CV (control voltage) ports for pitch, clock and gate; a 1/4-inch output for line-level audio; a USB port; plus a standard five-pin MIDI DIN. There's also a 1/4-inch input jack that not only accepts audio but also can do pitch tracking -- which means you could play the Motor Synth using a guitar, bass or even your voice. That said, we can't make any promises about how well the pitch tracking will work, since it's not up and running yet.
Now, while you can hook up a traditional keyboard and play the Motor Synth just like any other synthesizer, the folks at Gamechanger prefer to use the eight buttons on the front. These can be set to play any scale, making it easy to bang out a melody or bassline, even if you don't know how to play an instrument. And they can be either momentary (notes stop playing when you release the button) or latching (notes play until you play new notes). The latter is particularly useful for when you switch from free play to arpeggiator mode.
When you're using the arpeggiator, you'll definitely want to put the Motor Synth in mono or unison mode to avoid things getting cacophonous. When in unison it uses all eight motors simultaneously to play each note. The results are chest-rattling basslines and leads that are difficult to tame. This is definitely an instrument better suited to more-aggressive styles of electronic music like industrial or digital hardcore. (Is that still a thing?)
If you're going to use the Motor Synth in four-note polyphonic mode, your best bet is to hook up an external keyboard. While it's fun to jam on the eight-button front panel, it feels limiting when you're trying to play chords. Be aware that while you can play pads, they're going to be unlike anything you'd get on other synths. They're pretty rough around the edges, but not metallic. They'd probably make for a great horror movie score.