splines

scripts / norns

chorder

Chord instrument for Monome Norns

undisclosed Imported automatically; the author has not disclosed AI use yet

install

In maiden's REPL (the >> prompt at the bottom of the editor), run:

;install https://github.com/abhayadana/chorder

Or add the splines catalog to maiden and install it from the project manager. Restart norns if the script ships a new engine.

readme from abhayadana/chorder

Chorder

A four-voice chord-based instrument for Monome Norns.

  • Lanes / voices
    • Three performance lanes: Chord (main), Free Play A, and Free Play B
    • MIDI in currently supports only one input device but each lane can be targeted by a different channel
    • On Chord lane, white keys play diatonic chords (I-VII) in globally assigned key/scale. Black keys are used for momentary modifiers (assignable in parameters): 7th, 9th, sus2, sus4, or solo
    • Free Play lanes can play chords or solo
      • Free Play key input mode can be either: white keys (diatonic degrees), all keys - quantized to scale, or all keys chromatic (solo only)
    • The Arp lane receives chord information from the Chord lane.
    • Each output lane can target mx.samples, MIDI out, or both
    • nb voices work via nbout
  • Chord engine
    • Triads, 7th, 9th, sus2, sus4, inversions
    • Voicings:
      • None
      • Drop-2: second note from top down an octave
      • Drop-3: third note from top down an octave
      • Drop-2&4: 2nd and 4th from top down an octave
      • Drop-1: Top note down one octave
      • Open position: Keep at least a 5th between any adjacent notes
      • Wide spread: Move 3rd and 5th up an octave
      • Quartal: Rebuild chord in stacked 4ths from root
      • Quintal: Rebuild chord in stacked 5ths from root
      • Nearest voice leading: Each note moves by ≤ interval threshold (e.g., ≤5 semitones) to next chord
      • Smooth inversion: Auto-select inversion minimizing total motion from previous
  • Timing & feel
    • Global-clock aware quantize
    • Swing (grid/% modes)
    • Humanize (time/velocity)
    • Strum shapes:
      • Up: Straight low-to-high sweep
      • Down: Straight high-to-low sweep
      • Up/down: Up then down bounce back without repeating
      • Down/up: Down then up bounce back without repeating
      • Random: Random permutation
      • Center-out: Start at median note (if even, start at lower-middle) then alternate outward
      • Outside-in: alternate the edges inward
      • Bass-bounce: Keep returning to lowest note
      • Treble-bounce: Mirror of bass-bounce from the highest note
      • Random (no repeat first): Random order each cycle, but forbid immediate repeats of the previous cycle’s first note (also no back-to-back duplicates within the cycle)
      • Random (stable ends): Anchor first and last hits, randomize only the middle notes
      • Edge-kiss: Rapid outer-pair tap with tiny rebound inward, biased to keep returning to the edges
      • Ping-pair: Move in adjacent pairs with a serpentine: (1,2), (3,4), … (then) (N,N-1), (N-2,N-3)…; each pair is lightly rolled
      • Arp-chunk 2-3: Ascend in 2-note then 3-note chunks, repeating that 2/3 cadence: 1,2 | 3,4,5 | 6,7 | 8,9,10 ... (wrap if N < 5)
      • Guitar-rake: Fast low→high rake with slight decel and velocity falloff (classic strummed guitar upstroke vibe)
      • Harp-gliss split: Play the lower half quickly upwards, then the upper half quickly upwards
      • Arp-chunk 2-3 (down): Descending version of 2-3 chunks
      • Guitar-rake (down): High→low rake with slight decel and velocity falloff (downstroke)
      • Harp-gliss interleaved: Alternate halves like two hands trading, but both halves move inward each time (smoother than outside-in due to gliss timing)
      • Bass-random: Pick random notes but with a strong bias to hit the lowest note frequently (acts like a bass ostinato with flurries above)
      • Top-random: Random with a strong bias toward the highest note (sparkly top with occasional dips)
      • Outer random → mid: Start with outer notes chosen at random, then progressively bias toward the center; probability shifts from edges → middle across the phrase
      • Weave lo→hi: A rising serpentine: 1,2,1,3,2,4,3,5 ... (small backsteps while generally climbing)
      • Weave hi→lo: Mirror: N,N-1,N,N-2,N-1,N-3 ... (small backsteps while generally falling)
      • Inside-out (alt): Start near center; strictly alternate sides as you expand outward
      • Inside-out (random): Inside-out expansion but choose left/right randomly at each outward step
      • Odds then evens: Hit odd indices low→high, then even indices low→high: 1,3,5,..., 2,4,6,...
      • Evens then odds: The inverse ordering of Odds then evens
      • Low-half up / high-half down: Split at median: play lower half ascending, then upper half descending
  • Arppegiator (pattern library)
    • Patterns include basic (same as strum shapes above from Up to Treble-bounce) and "genre-specific" (according to ChatGPT)
    • Triggering modes: key-held and free-run
    • Timing divisions include triplets and dotted
    • Per-step probability
    • Ratchets and ratchet probability

Required

  • Monome Norns or equivalent
  • mx.samples engine & instrument packs installed at /home/we/dust/audio/mx.samples/
  • MIDI keyboard/controller (or Grid) for input & output. Chorder was developed and tested using a Novation Launchkey Mini MK3

Contributing

Pull requests & issues welcome!

Acknowledgements

discussion