The Mario theme on 8 motors — an octocopter case study

A friend showed up at a meetup with an X8 octo — eight motors, big lift, normally a cinema rig. They wanted to know what a real eight-voice arrangement would sound like coming out of it. We had two hours and a laptop. This is what we found.

Eight voices is a lot

On a quadcopter you're working with four monophonic lanes. That's enough for a melody, a bass, and one or two harmony parts. It's basically a string quartet.

Eight motors is more like a small ensemble. You can do:

• Melody (lead)
• Counter-melody
• Bass
• Sub-bass
• Three-note chord (alto + tenor + soprano)
• A drum / percussion line on the eighth

This is enough range to make standard four-part chorales sound full. The Mario theme, which is normally two voices (lead + bass) on a NES, can be expanded with a counter-melody and chord pads and start sounding like it's coming out of an actual band.

The setup

Octocopter: GEPRC Cinelog X8, eight 2806.5 motors at 1300 KV (these are heavy lifters, not racers). Bluejay on all eight ESCs. Frame is a big stiff carbon plate which projects sound well.

The MIDI we used was the standard Super Mario Bros. main theme from BitMidi — but the version with the harmony arrangement, not the chiptune original. That gave us 6 tracks to play with. We added a borrowed percussion track from a different Mario MIDI to fill the eighth voice.

How the converter handled it

We set Outputs to 8 and turned on track-to-motor affinity. The converter automatically distributed voices across the 8 motors, mostly correctly. We had to pin two notes manually where the chord allocation routed the wrong notes to the same motor at the same time, but the editor's pin-displace UI handled it cleanly.

Final note counts per motor: 47, 52, 38, 41, 33, 48, 51, 26. Comfortably under the 62-note limit. Nothing got dropped.

How it sounded

Loud. Really loud. Eight 2806.5s on a stiff carbon plate is basically an outdoor PA system. You could hear it from the far end of a football field.

The harmony actually came through. You can hear the chord progression underneath the melody, not just feel it. On a quad this would've been impossible — the bass would've eaten the harmony lane.

The biggest surprise was the percussion track. Even reduced to monophonic single-note "kicks" on a square wave, the rhythm pulse landed and made the whole arrangement feel grounded. I expected percussion to sound terrible on a motor. It sounded fine — like an 8-bit drum line.

What I'd do differently next time

• Spend more time on octave assignment. The bass and sub-bass overlapped at one point and the lower notes muddied things. A bit of manual octave-shift per track would've helped.
• Pick songs that benefit from polyphony. Mario was fun but a lot of pop songs have effectively three or four voices and just doubling them across 8 motors wastes the headroom. Try a Bach chorale or a four-part vocal arrangement.

Practical note for octocopter pilots

If you have an octo you almost certainly didn't build it for music. But it makes for a great PA at events. Pre-arm chord progression, anyone?

You'll need to flash Bluejay on all eight ESCs and use a configurator that handles 8 motors (esc-configurator does). Beyond that, the converter supports up to 8 outputs out of the box.