| project name: | nørgård |
| project url: | https://github.com/frederickk/noergaard |
| author: | frederickk |
| description: | A small library to generate Nørgård infinity sequences for Norns |
| tags: | sequencer generative midi |
Nørgård
v0.1.1
A small library to generate Nørgård infinity sequences for Norns.
Thank you to Ezra Buchla for his lua Nørgård algorithm and Lawton Hall for his Nørgård SuperCollider algorithms.
Install
You can install this library and demos via Maiden. Be sure to refresh the Community lists, and look for nørgård.
Otherwise, if you’re a developer, pull down the library from Github and checkout the API below.
Usage
Look at the demos to see how the library can be used. The library itself is lib/noergaard.lua just add that file to your scripts folder, wherever you chose (I prefer lib/). Then add the following to your script.
local noergaard = include("path/to/noergaard")
Demos
Along with the library are 3 demos showing how to use the library.
noergaard-simple
Generates Nørgård infinity series and played using the PolyPerc engine. There are no controls, it just starts and goes on… infinitely
noergaard-sequencer
A fairly simple sequencer that plays infinity sequence — uses PolyPerc engine and also outputs Midi notes (to device 1).
| Page | Controller | Description | Values |
|---|---|---|---|
| All | E1 | Change page | |
| 1 | E2 | BPM | 20 - 300 |
| 1 | E3 | note length | 1/256 - 4 |
| 2 | E2 | Midi root | C-2 - C8 |
| 2 | E3 | Scale type (see norns/musicutil.lua for full list); 0 = scale determined naturally by algorithm | 0 - 46 |
| 3 | E2 | Step | 1 – 12 |
| 3 | E3 | Sequence length; 0 = maximum (or 480) | 0 - 320 |
| 4 | E2 | Loop at length | true (1) or false (0) |
| 4 | E3 | Increment | 1 - 8 |
noergaard-chords
Generate chords from infinity series intervals — uses PolyPerc engine and also outputs Midi notes (to device 1). Thanks to Devine Lu Linvega for the keyboard.
| Page | Controller | Description | Values |
|---|---|---|---|
| All | E1 | Change page | |
| 1 | E2 | BPM | 20 - 300 |
| 1 | E3 | note length | 1/256 - 4 |
| 2 | E2 | Midi root | C-2 - C8 |
| 2 | E3 | Chord type (see norns/musicutil.lua for full list); 0 = build chord from sequence notes using amount determined by Chord length |
0 - 26 |
| 3 | E2 | Step | 1 – 12 |
| 3 | E3 | Sequence length; 0 = maximum (or 480) | 0 - 320 |
| 4 | E2 | Loop at length | true (1) or false (0) |
| 4 | E3 | Chord length; only applies when Chord type is set to Noergaard |
2 - 9 |
API
Noergaard.compute(t, step)
Nørgård algorithm to compute intervals. Thank you @zebra! https://llllllll.co/t/35657/9
Parameters
t a table containing at least 2 values
step (optional, default=1) new interval step
Returns
nothing; new value is appended to the table in-place
Noergaard.integer(index)
Returns integer in infinity series by index. https://www.lawtonhall.com/blog/2019/9/9/per-nrgrds-infinity-series
Parameters
index index of infinity series to calculate
Returns
Nørgård number
Noergaard.compute_subset(start_index, end_index)
Populates intervals table with Nørgård integers within a given range. https://www.lawtonhall.com/blog/2019/9/9/per-nrgrds-infinity-series
Parameters
start_index starting index of infinity series
end_index ending index of infinity series
Noergaard.step()
Adds interval to table, based on “start” and “step” params.
Noergaard.get_step()
Gets step increment.
Returns
Step interval
Noergaard.get_interval(index)
Gets interval.
Parameters
index (optional) interval index; no index returns last added interval
Returns
Interval
Noergaard.get_midi_note(index)
Gets Midi note number.
Parameters
index (optional) note index; no index returns last added note
Returns
Midi note number
Noergaard.get_midi_note_scale(scale_type, index)
Gets Midi note number, snapped to given scale.
Parameters
scale_type String defining scale type (eg, “major”, “aeolian” or “neapolitan major”), see “musicutil” class for full list.
index (optional) note index; no index returns last added note
Returns
Midi note number
Noergaard.get_midi_root()
Gets Midi root note as name + octave e.g. “C4”.
Returns
Midi root note
Noergaard.get_note_name(index)
Gets Midi note name e.g. “C”.
Parameters
index (optional) note index; no index returns last added note
Returns
Midi note name
Noergaard.get_note_freq(index)
Gets note as frequency name e.g. C4 => “261.63”.
Parameters
index (optional) note index; no index returns last added note
Returns
Note frequency
Noergaard.get_note_freq_scale(scale_type, index)
Gets note as frequency name e.g. C4 => “261.63”, mapped to given scale
Parameters
scale_type String defining scale type (eg, “major”, “aeolian” or “neapolitan major”), see “musicutil” class for full list.
index (optional) note index; no index returns last added note
Returns
Note frequency
Noergaard.set_octave(index)
Sets octave to lock Midi notes to.
Parameters
index (optional) Midi octave value -2 to 8; no index sets octave to “Natural”.
Noergaard.get_octave()
Gets octave as string.
Returns
Octave value
Params
params:set("noergaard_start", num)
Sets seed starting value, setting/changing this will reset the interval values table; default = 0
params:get("noergaard_start")
Returns seed starting value
Range
0 – 12
params:set("noergaard_step", num)
Sets seed step value, setting/changing this will reset the interval values table; default = 1
params:get("noergaard_step")
Returns seed step value
Range
1 – 12
params:set("noergaard_midi_root", num)
Sets root (starting) note for all Midi subsequent notes.
params:get("noergaard_midi_root")
Returns Midi root (starting) note as number
Range
0 – 128
params:set("noergaard_octave", num)
Sets octave for notes returned any value above 0 locks the returned notes to that octave; default = 0 (or Natural)
params:get("noergaard_octave")
Range
- 0: Natural, i.e. what the algorithm would naturally generate
- 1: -2
- 2: -1
- 3: 0
- 4: 1
- 5: 2
- 6: 3
- 7: 4
- 8: 5
- 9: 6
- 10: 7
- 11: 8
params:set("noergaard_len", num)
Sets a specific maximum number for intervals, a value of 0 means no defined length, but the maximum is 480; default = 0
params:get("noergaard_len")
Range
0 – 480