MIDI Implementation

[ghost]

I've come up with a way to use your app to drive external synths and drum machines using WebMIDI (currently supported by Chrome).

There's a squashed commit here that has a rough draft: https://github.com/nagytech/acid-banger/commit/bf0cc4764623ec82bb618f7c13c0655516fc0f6e

I'm wondering if you would be interested in this as a feature. And, if you might have some insight on how you would offer the user the option to select a MIDI output (if found and supported).

I'll continue to clean up my implementation, hopefully it will be less of a hack soon.

Summary

• Notes for saw osc are sent to MIDI channel 8
• Notes for square osc are sent to MIDI channel 9
• Drum tracks are sent to channels 1,2,3 and 4 using note 35

TODO

• Velocity is set to a static value, will need to map this to the appropriate MIDI values
• Filter values, accents and glides are not implemented yet (will need to look up the right CC values for this)
• Different synths will have different retrig rules, so ties (glide) notes might be tricky to implement - I can do what works for me, but no guarantee it works for others.

Hardware

WebMIDI Out -> Digitakt MIDI via USB -> Tracks 1-4 -> Drum Samples
                                        Tracks 10-11 -> MIDI Out -> MIDI to CV -> Synth A/B

Demo

https://user-images.githubusercontent.com/8542033/115423752-6e2dc780-a241-11eb-950f-3086676b8efd.mp4

[doctea]

Instead of using separate MIDI channels for the different drum tracks, I'd suggest using the GM standard channel 10 for percussion: https://en.wikipedia.org/wiki/General_MIDI#Percussive

[vitling]

Great stuff! I'm really glad that you have been so inspired to add MIDI support for this and the video looks really cool - I wish I had that kind of gear to play with then maybe I wouldn't have to write so much software to do it instead :-D

For the time being I consider the version I released online to be "complete" in terms of having all the features that I wanted it to have. I've added a small note about that to the README. I do, however, strongly encourage you to keep working on your MIDI version if you want to, and I'll happily share your fork across my networks if it ends up working well.

[ghost]

Instead of using separate MIDI channels for the different drum tracks, I'd suggest using the GM standard channel 10 for percussion: https://en.wikipedia.org/wiki/General_MIDI#Percussive

Sounds like a good idea, but my gear already has separate channels for each track. I have no way to test or validate the alternative protocol.

[ghost]

For the time being I consider the version I released online to be "complete" in terms of having all the features that I wanted it to have. I've added a small note about that to the README.

No worries, I'll close this one then.