Concertina MIDI Controller

Oh gosh, this is amazing! I would love to hear/see it in action. Do you have a synthesizer you can drive?

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Beautiful and impressive!

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That may be the most ridiculous thing I’ve seen created with a Glowforge! And I mean that in the most positive way! :slight_smile: I’m actually sitting here smiling ear to ear at how awesome that thing is.

I see you have a pressure sensor in there. So you’re actually getting velocity sensitivity out of this?! Holy crap that’s awesome!

DAMN this is cool.

Does the Bluefeather give you Bluetooth MIDI?!

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Wonderful unique Project! Thank you for sharing your progress!

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In a “normal” concertina, bellows air pressure causes the reeds to vibrate when you press buttons. In this one, the bellows pressure is just measured and used to tell the synthesizer how loud the sounds should be. Pressing a button tells the synthesizer to start playing the corresponding note and releasing the button tells the synthesizer to stop playing that note. With no synthesizer connected, there is no sound. With a synthesizer connected, it sounds like whatever instrument I tell the synthesizer to pretend to be – trumpet, bells, accordion, etc. Even a concertina. :wink:

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I’m glad you liked it.

Yes, the pressure sensor is used to set how loudly the notes play. Technically, the notes are all played with maximum velocity and the pressure sensor sets what’s called the “expression” which sets the overall loudness of whatever notes are currently playing. If I press and hold some buttons to play a chord and then vary the bellows pressure, the loudness varies accordingly.

And, yes, the Bluefeather does MIDI over Bluetooth LE. A library Adafruit provides makes MIDI over Bluetooth really, really simple.

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That’s interesting. Is that a true representation of how concertinas play? I’ve never played one. But it’s funny that I was explaining the difference to somebody just the other day… How a piano key pressed as hard as possible, but at a low volume, is not the same as pressing a piano key lightly. And for many instruments that holds true. But some it’s purely a matter of volume as opposed to timbre.

I’ve GOTTA get into Adafruit stuff. So many cool things to make with!
Wonder if I could use this to make a guitar MIDI controller. I’ll have to research that!

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Totally cool project!

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Totally awed by this project. I remember the concertinas from my childhood. There were always a few street musicians with them in Amsterdam.

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Yes, that’s pretty much how concertinas play. At least to the first approximation.

On a traditional concertina, pressing a button lifts a pad covering a hole in the reed pan. This allows air to move across the corresponding reed causing it to vibrate. The bellows pressure at the time the button is first pressed determines how rapidly the vibration starts and which of the reed’s harmonics are emphasized in the process. That allows the player to change a note’s “attack.” Once a note is sounding, changing the pressure mostly changes the volume at which the note plays, but there are also some (minor) changes in timbre due to changes to the way the reed vibrates at different pressures.

Unlike a piano, changes in the speed with which a button is pressed has little effect on the sound – especially compared to the effect of bellows pressure.

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The synthesizer I’ve been testing with runs on my phone. (Building a “good” one is my next project.) Here’s a short vid on Vimeo showing how that works.

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I am so in love with this project! Wow! I was looking at concertinas this summer. How fun to run across your post. It’s fantastic! I can’t wait to hear it played. I’ll hit Vimeo and then over to hackaday. Smart people rock!

Edit: Just watched video. My mind is blown. My favorite line is the last, “Anyway, that’s what it does.” I love the app and that the concertina can play in a variety of styles. This is an amazing project!

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@rebecca I’m glad you liked it. It’s been a fun project. I’m really happy that it’s come along far enough that I can play it while I work on it!

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you lost me at Concertina MIDI Controller but I love the design and detail

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@friki-tiki It’s been a great deal of fun to design and build. The precision with which the pieces are cut is just wonderful and a joy to behold. Without the :glowforge: it simply would not have been possible. It’s a great – not perfect, but great – tool for things like this.

This is amazing. Delrin is the perfect choice for the buttons. Wowed and amazed !

That is super cool!

I know this is an old post, but I just had to jump in here and say wow.

The details and styling are beautiful, and the technical build is genius! Using expression instead of velocity is definitely the right way to go. And you managed to make this completely wireless!

This reminds me of the Roland MIDI Accordion. (In the hands of a talented musician, it doesn’t even sound like an accordion!)

Form, function, and style. Thank you so much for sharing this!

Love it!

Thanks for the kind words.

Since I posted this, I did go ahead and build a synthesizer for the concertina to attach to. It’s based on a Raspberry Pi 3b+ and Fluidsynth. I wrote a custom GUI application in C++ using the Qt toolkit to control the synth – instrument selection, volume, reverb, etc. Here’s what it looks like:

It’s about 10cm x 7cm x 7cm, so pretty compact. The case is made from stacked sheets of acrylic cut (on the GF, naturally) to fit the electronic bits – the Pi, screen and amplifier – and to let the blinkenlights shine through. The screen is touch sensitive, so controlling the synth is done by poking and sliding.

After I initially made the concertina, I’ve tweaked the the function that maps measured bellows pressure to MIDI expression several times as I gained experience in playing it, but haven’t touched it in quite a while now, even though I use it nearly every day.

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