A probabilistic 4-track sequencer for MIDI, Molly the Poly, and Crow.

  • Inspired by Turing Machine, Fugue Machine, and Physical (Norns Study 4).
  • I originally wrote this sequencer in November of 2018, but never updated it to be compatible with Norns 2.0. I always intended on doing so, but never prioritized it ahead of work, young kids and other projects.
  • Then last week I got an email out of the blue from ground_state who had updated it to 2.0 and added audio output via Molly the Polly. Super grateful to this community member for updating the script, improving it and cleaning up my bad code. It’s been a pleasure to work with him the last couple of days to finish it up. I expect he’ll be doing some interesting new scripts for Norns in the coming months.
  • ground_state has some cool ideas for enhancements to Quence, so hopefully we’ll release a new version sometime soon.
  • justmat added the ability to output to Crow (Just Friends and CV).


Grid, MIDI Interface required to output MIDI (optional), Crow (optional)


  • There are 5 pages in total, a settings page and 4 track pages.
  • After launching the script, the track page for Track One will be visible and the sequencer will be paused.
  • The bottom row is always the toolbar: pause, mutes for tracks 1-4, lock all, clear all, select tracks 1-4, and settings page.
  • The LED in the bottom right corner toggles between the current track page and the settings page.
  • The LED in the bottom left corner toggles the sequencer pause.
  • On the settings page, the eight buttons in rows 5-6, cols 13-16 are currently unassigned.
  • For now, pressing any of these LEDs will re-sync all sequences.
  • Hold Key 3 on the Norns to see the midi notes in the sequence for the current track.




  • Global tempo, tonic and scale.
  • There are 4 independent tracks of 1-16 steps.
  • Each MIDI track is sent to the channel equal to the track number.
  • Each track has a tempo modifier (1 is global bpm, 8 is global bpm divided by 8).
  • Each track has a dispersion parameter (1 is a tight dispersion of notes, 10 is a very high dispersion of notes).
  • Each track has a randomization parameter (1 is locked sequence, 8 is completely random).
  • Each track has a rest frequency parameter (1 is no rests, 8 is no notes).
  • Each track can be muted.
  • Each track can be copied and pasted into another track.
  • Each track can be transposed up or down a scale degree.
  • Each track can be shifted forward or backward one step.
  • Each track can be inverted or reversed.
  • All tracks can be locked or cleared simultaneously.
  • Tracks can be re-synced if tempo modification un-syncs them.

very very nice. not going to be near my norns today…does it talk with JF over i2c or cv out with crow?

1 Like

No, crow is currently unsupported.

Looking forward to this one! Congrats:)

If you’re up for it, we could use someone who owns a crow to try it out (it should be easy to add support to the script: if that’s outside of your current experience level, but you’re still willing to test, just let us know :))


I have a crow, and the code looks approachable :slight_smile: I will give it a shot when I get the chance.


i too have a crow, but @Justmat is infinitely more qualified to dig into it :slight_smile:

will be happy to test out and give feedback of course


Not to put too fine a point on it, but I think @spunoza’s downplaying his own work here :slight_smile:

Due to the way it’s architected, the above are all continuous, e.g. shifting a sequence “one step” can be repeated until you’re back where you started; tracks can be transposed up or down “a” scale degree until you go sub-/ultra- sonic.

To definitely toot my own horn; reverse playback does just that (a la e.g. Fugue Machine) - the sequence isn’t reversed in place, it actually plays back in reverse.


playing with this now and really digging it! Crow out will be super simple, I should have a PR ready tomorrow. I’m planning on doing crow -> just friends, and crow -> cv outs. I’ll just add them to the output options param as crow jf and crow cv. :partying_face:


Just noticed that Quence has been added to the Norns Community repo and can now be installed via Maiden’s project manager. :+1:


Just a quick update, I have the crow stuff working! Took me a couple days to find the time :sweat_smile: Gonna play with it for the evening, and assuming I didn’t muck something up, I’ll open a PR.

@spunoza, and @ground_state have done an excellent job with this script!


@Justmat; Nice! You might want to pull and rebase - I pushed a couple of bugfix PRs and spunoza merged them.

1 Like

Rebased and pushed my changes :partying_face: PR away


I was playing around with adding the option to have a different output for each track. I had a question about Crow and Just Friends (I don’t have either).

Is it possible to use both JF mode and CV mode in the same script? The reason I ask is because in JF mode crow.ii.pullup is ‘true’ and crow.ii.jf.mode = 1, but ‘false’ and 0 in CV mode. Does that mean I can’t have one track in JF mode and another in CV mode?

1 Like

The crow.ii.jf.mode line is using Crow to put Just Friends into “synthesis” mode. This is necessary if you are using JF as a synth voice but should be set to 0 for normal use.

The crow.ii.pullup line is just setting the i2c pullup resistors, which is needed if you are using the i2c bus. (output == crow jf is, while output == crow cv is not.)

You can have this active(or not) while doing other things, like using output == crow cv outputs.

Ok, I’ll give it a try. Thanks!

1 Like

Is there any way to get this going without a grid? It looks fantastic!

1 Like

No. It requires a grid or a DIY grid. I have a version that works with a midi fighter twister, but I never updated it to Norns 2.0.

1 Like

Hmm, if the midi fighter twister worked do you think I could get it working with a Livid Instruments Code?

I would expect so. Does it have multiple banks, like a twister? The twister is only 4x4, but you have 4 banks to switch between.

Take a look at my twister code for some ideas on how to adapt to it. (The code is still Norns 1.0).

Good luck! Looks like a great controller.