import { MiniRepl } from './MiniRepl';

# Table of Contents

# What is Strudel?

With Strudel, you can expressively write dynamic music pieces.
It aims to be [Tidal Cycles](https://tidalcycles.org/) for JavaScript (started by the same author).

You don't need to know JavaScript or Tidal Cycles to make music with Strudel.

This interactive tutorial will guide you through the basics of Strudel.

The best place to actually make music with Strudel is the [Strudel REPL](https://strudel.tidalcycles.org/).

## Show me a Demo

To get a taste of what Strudel can do, check out this track:

<MiniRepl
  tune={`const delay = new FeedbackDelay(1/8, .4).chain(vol(0.5), out());
const kick = new MembraneSynth().chain(vol(.8), out());
const snare = new NoiseSynth().chain(vol(.8), out());
const hihat = new MetalSynth().set(adsr(0, .08, 0, .1)).chain(vol(.3).connect(delay),out());
const bass = new Synth().set({ ...osc('sawtooth'), ...adsr(0, .1, .4) }).chain(lowpass(900), vol(.5), out());
const keys = new PolySynth().set({ ...osc('sawtooth'), ...adsr(0, .5, .2, .7) }).chain(lowpass(1200), vol(.5), out());
const drums = stack(
"c1*2".tone(kick).bypass("<0@7 1>/8"),
"~ <x!7 [x@3 x]>".tone(snare).bypass("<0@7 1>/4"),
"[~ c4]*2".tone(hihat)
);
const thru = (x) => x.transpose("<0 1>/8").transpose(-1);
const synths = stack(
"<eb4 d4 c4 b3>/2".scale(timeCat([3,'C minor'],[1,'C melodic minor']).slow(8)).struct("[~ x]\*2")
.layer(
scaleTranspose(0).early(0),
scaleTranspose(2).early(1/8),
scaleTranspose(7).early(1/4),
scaleTranspose(8).early(3/8)
).layer(thru).tone(keys).bypass("<1 0>/16"),
"<C2 Bb1 Ab1 [G1 [G2 G1]]>/2".struct("[x [~ x] <[~ [~ x]]!3 [x x]>@2]/2".fast(2)).layer(thru).tone(bass),
"<Cm7 Bb7 Fm7 G7b13>/2".struct("~ [x@0.1 ~]".fast(2)).voicings().layer(thru).every(2, early(1/8)).tone(keys).bypass("<0@7 1>/8".early(1/4))
)
stack(
drums.fast(2),
synths
).slow(2);
`}
/>

[Open this track in the REPL](https://strudel.tidalcycles.org/#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%2BLzgnLm0pLAogICAgJ34gPHghNyBbeEAzIHhdPicubS50b25lKHNuYXJlKS5ieXBhc3MoJzwwQDcgMT4vNCcubSksCiAgICAnW34gYzRdKjInLm0udG9uZShoaWhhdCkKICApOwogIAogIGNvbnN0IHRocnUgPSAoeCkgPT4geC50cmFuc3Bvc2UoJzwwIDE%2BLzgnLm0pLnRyYW5zcG9zZSgtMSk7CiAgY29uc3Qgc3ludGhzID0gc3RhY2soCiAgICAnPGViNCBkNCBjNCBiMz4vMicubS5zY2FsZSh0aW1lQ2F0KFszLCdDIG1pbm9yJ10sWzEsJ0MgbWVsb2RpYyBtaW5vciddKS5zbG93KDgpKS5ncm9vdmUoJ1t%2BIHhdKjInLm0pCiAgICAuZWRpdCgKICAgICAgc2NhbGVUcmFuc3Bvc2UoMCkuZWFybHkoMCksCiAgICAgIHNjYWxlVHJhbnNwb3NlKDIpLmVhcmx5KDEvOCksCiAgICAgIHNjYWxlVHJhbnNwb3NlKDcpLmVhcmx5KDEvNCksCiAgICAgIHNjYWxlVHJhbnNwb3NlKDgpLmVhcmx5KDMvOCkKICAgICkuZWRpdCh0aHJ1KS50b25lKGtleXMpLmJ5cGFzcygnPDEgMD4vMTYnLm0pLAogICAgJzxDMiBCYjEgQWIxIFtHMSBbRzIgRzFdXT4vMicubS5ncm9vdmUoJ1t4IFt%2BIHhdIDxbfiBbfiB4XV0hMyBbeCB4XT5AMl0vMicubS5mYXN0KDIpKS5lZGl0KHRocnUpLnRvbmUoYmFzcyksCiAgICAnPENtNyBCYjcgRm03IEc3YjEzPi8yJy5tLmdyb292ZSgnfiBbeEAwLjEgfl0nLm0uZmFzdCgyKSkudm9pY2luZ3MoKS5lZGl0KHRocnUpLmV2ZXJ5KDIsIGVhcmx5KDEvOCkpLnRvbmUoa2V5cykuYnlwYXNzKCc8MEA3IDE%2BLzgnLm0uZWFybHkoMS80KSkKICApCiAgcmV0dXJuIHN0YWNrKAogICAgZHJ1bXMuZmFzdCgyKSwgCiAgICBzeW50aHMKICApLnNsb3coMik7Cn0%3D)

## Disclaimer

- This project is still in its experimental state. In the future, parts of it might change significantly.
- This tutorial is far from complete.

<br />

# Mini Notation

Similar to Tidal Cycles, Strudel has an embedded mini language that is designed to write rhythmic patterns in a short manner.
Before diving deeper into the details, here is a flavor of how the mini language looks like:

<MiniRepl
  tune={`\`[
  [
    [e5 [b4 c5] d5 [c5 b4]]
    [a4 [a4 c5] e5 [d5 c5]]
    [b4 [~ c5] d5 e5]
    [c5 a4 a4 ~]
    [[~ d5] [~ f5] a5 [g5 f5]]
    [e5 [~ c5] e5 [d5 c5]]
    [b4 [b4 c5] d5 e5]
    [c5 a4 a4 ~]
  ],[
    [[e2 e3]*4]
    [[a2 a3]*4]
    [[g#2 g#3]*2 [e2 e3]*2]
    [a2 a3 a2 a3 a2 a3 b1 c2]
    [[d2 d3]*4]
    [[c2 c3]*4]
    [[b1 b2]*2 [e2 e3]*2]
    [[a1 a2]*4]
  ]
]/16\``}
/>

The snippet above is enclosed in backticks (`), which allows you to write multi-line strings.
You can also use double quotes (") for single line mini notation.

## Notes

Notes are notated with the note letter, followed by the octave number. You can notate flats with `b` and sharps with `#`.

<MiniRepl tune={`"e5"`} />

Here, the same note is played over and over again, once a second. This one second is the default length of one so called "cycle".

By the way, you can edit the contents of the player, and press "update" to hear your change!
You can also press "play" on the next player without needing to stop the last one.

## Sequences

We can play more notes by separating them with spaces:

<MiniRepl tune={`"e5 b4 d5 c5"`} />

Here, those four notes are squashed into one cycle, so each note is a quarter second long.

## Division

We can slow the sequence down by enclosing it in brackets and dividing it by a number:

<MiniRepl tune={`"[e5 b4 d5 c5]/2"`} />

The division by two means that the sequence will be played over the course of two cycles.
You can also use decimal numbers for any tempo you like.

## Angle Brackets

Using angle brackets, we can define the sequence length based on the number of children:

<MiniRepl tune={`"<e5 b4 d5 c5>"`} />

The above snippet is the same as:

<MiniRepl tune={`"[e5 b4 d5 c5]/4"`} />

The advantage of the angle brackets, is that we can add more children without needing to change the number at the end.

## Multiplication

Contrary to division, a sequence can be sped up by multiplying it by a number:

<MiniRepl tune={`"[e5 b4 d5 c5]*2"`} />

The multiplication by 2 here means that the sequence will play twice a cycle.

## Bracket Nesting

To create more interesting rhythms, you can nest sequences with brackets, like this:

<MiniRepl tune={`"e5 [b4 c5] d5 [c5 b4]"`} />

## Rests

The "~" represents a rest:

<MiniRepl tune={`"[b4 [~ c5] d5 e5]"`} />

## Parallel

Using commas, we can play chords:

<MiniRepl tune={`"g3,b3,e4"`} />

To play multiple chords in a sequence, we have to wrap them in brackets:

<MiniRepl tune={`"<[g3,b3,e4] [a3,c3,e4] [b3,d3,f#4] [b3,e4,g4]>"`} />

## Elongation

With the "@" symbol, we can specify temporal "weight" of a sequence child:

<MiniRepl tune={`"<[g3,b3,e4]@2 [a3,c3,e4] [b3,d3,f#4]>"`} />

Here, the first chord has a weight of 2, making it twice the length of the other chords. The default weight is 1.

## Replication

Using "!" we can repeat without speeding up:

<MiniRepl tune={`"<[g3,b3,e4]!2 [a3,c3,e4] [b3,d3,f#4]>"`} />

In essence, the `x!n` is like a shortcut for `[x*n]@n`.

## Euclidian

Using round brackets, we can create rhythmical sub-divisions based on three parameters: beats, segments and offset.
The first parameter controls how may beats will be played.
The second parameter controls the total amount of segments the beats will be distributed over.
The third (optional) parameter controls the starting position for distributing the beats.
One popular Euclidian rhythm (going by various names, such as "Pop Clave") is "(3,8,1)" or simply "(3,8)",
resulting in a rhythmical structure of "x ~ ~ x ~ ~ x ~" (3 beats over 8 segments, starting on position 1).

<MiniRepl tune={`"e5(2,8) b4(3,8) d5(2,8) c5(3,8)".slow(4)`} />

<br />

# Web Audio Output

The default way to output sound is by using the Web Audio Output.
Here is a little beat to show some of the possibilities:

<MiniRepl
  tune={`samples({
  bd: ['bd/BT0AADA.wav','bd/BT0AAD0.wav','bd/BT0A0DA.wav','bd/BT0A0D3.wav','bd/BT0A0D0.wav','bd/BT0A0A7.wav'],
  sd: ['sd/rytm-01-classic.wav','sd/rytm-00-hard.wav'],
  hh: ['hh27/000_hh27closedhh.wav','hh/000_hh3closedhh.wav'],
}, 'github:tidalcycles/Dirt-Samples/master/');
stack(
s("bd,[~ <sd!3 sd(3,4,2)>],hh(3,4)") // drums
.speed(perlin.range(.7,.9)) // random sample speed variation
,"<a1 b1\*2 a1(3,8) e2>" // bassline
.off(1/8,x=>x.add(12).degradeBy(.5)) // random octave jumps
.add(perlin.range(0,.5)) // random pitch variation
.superimpose(add(.05)) // add second, slightly detuned voice
.n() // wrap in "n"
.decay(.15).sustain(0) // make each note of equal length
.s('sawtooth') // waveform
.gain(.4) // turn down
.cutoff(sine.slow(7).range(300,5000)) // automate cutoff
,"<Am7!3 <Em7 E7b13 Em7 Ebm7b5>>".voicings() // chords
.superimpose(x=>x.add(.04)) // add second, slightly detuned voice
.add(perlin.range(0,.5)) // random pitch variation
.n() // wrap in "n"
.s('sawtooth') // waveform
.gain(.16) // turn down
.cutoff(500) // fixed cutoff
.attack(1) // slowly fade in
)
.slow(3/2)
.out()`}
/>

## Synths

So far, all the mini notation examples all used the same sound, which is kind of boring.
We can change the sound, using the `s` function:

<MiniRepl tune={`note("c2 <eb2 <g2 g1>>").s('sawtooth').out()`} />

Here, we are wrapping our notes inside `note` and set the sound using `s`, connected by a dot.

Those functions are only 2 of many ways to alter the properties, or _params_ of a sound.
The power of patterns allows us to sequence any _param_ independently:

<MiniRepl tune={`note("c2 <eb2 <g2 g1>>").s("<sawtooth square triangle>").out()`} />

Now we not only pattern the notes, but the sound as well!
`sawtooth` `square` and `triangle` are the basic waveforms available in `s`.

### Envelope

You can control the envelope of a synth using the `attack`, `decay`, `sustain` and `release` functions:

<MiniRepl
  tune={`note("c2 <eb2 <g2 g1>>").s('sawtooth')
  .attack(.1).decay(.1).sustain(.2).release(.1).out()`}
/>

## Samples

Besides Synths, `s` can also play back samples:

<MiniRepl tune={`s("bd sd,hh*8,misc/2").out()`} />

To know which sounds are available, open the [default sample map](https://strudel.tidalcycles.org/EmuSP12.json)

### Custom Sample Maps

You can load your own sample map like this:

<MiniRepl
  tune={`samples({
  bd: 'bd/BT0AADA.wav',
  sd: 'sd/rytm-01-classic.wav',
  hh: 'hh27/000_hh27closedhh.wav',
}, 'https://raw.githubusercontent.com/tidalcycles/Dirt-Samples/master/');
s("bd sd,hh*8").out()`}
/>

The `samples` function takes an object that maps sound names to audio file paths.
The second argument is the base URL that comes before each path. Make sure your base URL ends with a slash, while your sample paths do **not** begin with one.

Because github is a popular choice to dump samples, there is a shortcut for that:

<MiniRepl
  tune={`samples({
  bd: 'bd/BT0AADA.wav',
  sd: 'sd/rytm-01-classic.wav',
  hh: 'hh27/000_hh27closedhh.wav',
}, 'github:tidalcycles/Dirt-Samples/master/');
s("bd sd,hh*8").out()`}
/>

The format is `github:user/repo/branch/`.

### Multiple Samples per Sound

It is also possible, to declare multiple files for one sound, using the array notation:

<MiniRepl
  tune={`samples({
  bd: ['bd/BT0AADA.wav','bd/BT0AAD0.wav'],
  sd: ['sd/rytm-01-classic.wav','sd/rytm-00-hard.wav'],
  hh: ['hh27/000_hh27closedhh.wav','hh/000_hh3closedhh.wav'],
}, 'github:tidalcycles/Dirt-Samples/master/');
s("<bd:0 bd:1>,~ <sd:0 sd:1>,[hh:0 hh:1]*2").out()`}
/>

The `:0` `:1` etc. are the indices of the array.
The sample number can also be set using `n`:

<MiniRepl
  tune={`samples({
  bd: ['bd/BT0AADA.wav','bd/BT0AAD0.wav'],
  sd: ['sd/rytm-01-classic.wav','sd/rytm-00-hard.wav'],
  hh: ['hh27/000_hh27closedhh.wav','hh/000_hh3closedhh.wav'],
}, 'github:tidalcycles/Dirt-Samples/master/');
s("bd,~ sd,hh*4").n("<0 1>").out()`}
/>

### Pitched Sounds

For pitched sounds, you can use `note`, just like with synths:

<MiniRepl
  tune={`samples({
  "gtr": 'gtr/0001_cleanC.wav',
}, 'github:tidalcycles/Dirt-Samples/master/');
note("g3 [bb3 c4] <g4 f4 eb4 f3>@2").s('gtr').gain(.5).out()`}
/>

Here, the guitar samples will overlap, because they always play till the end.
If we want them to behave more like a synth, we can add `clip(1)`:

<MiniRepl
  tune={`samples({
  "gtr": 'gtr/0001_cleanC.wav',
}, 'github:tidalcycles/Dirt-Samples/master/');
note("g3 [bb3 c4] <g4 f4 eb4 f3>@2").s('gtr').clip(1)
  .gain(.5).out()`}
/>

### Base Pitch

If we have 2 samples with different base pitches, we can make them in tune by specifying the pitch like this:

<MiniRepl
  tune={`samples({
  "gtr": 'gtr/0001_cleanC.wav',
  "moog": { 'g3': 'moog/005_Mighty%20Moog%20G3.wav' },
}, 'github:tidalcycles/Dirt-Samples/master/');
note("g3 [bb3 c4] <g4 f4 eb4 f3>@2").s("gtr,moog").clip(1)
  .gain(.5).out()`}
/>

If a sample has no pitch set, `c3` is the default.

We can also declare different samples for different regions of the keyboard:

<MiniRepl
  tune={`samples({
  "moog": {
    'g2': 'moog/004_Mighty%20Moog%20G2.wav',
    'g3': 'moog/005_Mighty%20Moog%20G3.wav',
    'g4': 'moog/006_Mighty%20Moog%20G4.wav',
  }}, 'github:tidalcycles/Dirt-Samples/master/');
note("g2!2 <bb2 c3>!2, <c4@3 [<eb4 bb3> g4 f4]>")
  .s('moog').clip(1)
  .gain(.5).out()`}
/>

The sampler will always pick the closest matching sample for the current note!

## Effects

Wether you're using a synth or a sample, you can apply these effects:

{{ 'cutoff' | jsdoc }}

{{ 'resonance' | jsdoc }}

{{ 'hcutoff' | jsdoc }}

{{ 'hresonance' | jsdoc }}

{{ 'bandf' | jsdoc }}

{{ 'bandq' | jsdoc }}

{{ 'vowel' | jsdoc }}

{{ 'pan' | jsdoc }}

{{ 'coarse' | jsdoc }}

{{ 'shape' | jsdoc }}

{{ 'crush' | jsdoc }}

<br />

# Core API

While the mini notation is powerful on its own, there is much more to discover.
Internally, the mini notation will expand to use the actual functional JavaScript API.

## Notes

Notes are automatically available as variables:

<MiniRepl tune={`seq(d4, fs4, a4)`} />

An important difference to the mini notation:
For sharp notes, the letter "s" is used instead of "#", because JavaScript does not support "#" in a variable name.

The above is the same as:

<MiniRepl tune={`seq('d4', 'f#4', 'a4')`} />

Using strings, you can also use "#".

## Functions that create Patterns

The following functions will return a pattern. We will see later what that means.

## pure(value)

To create a pattern from a value, you can wrap the value in pure:

<MiniRepl tune={`pure('e4')`} />

Most of the time, you won't need that function as input values of pattern creating functions are purified by default.

### cat(...values)

The given items are con**cat**enated, where each one takes one cycle:

<MiniRepl tune={`cat(e5, b4, [d5, c5])`} />

- Square brackets will create a subsequence
- The function **slowcat** does the same as **cat**.

### seq(...values)

Like **cat**, but the items are crammed into one cycle:

<MiniRepl tune={`seq(e5, b4, [d5, c5])`} />

- Synonyms: **fastcat**, **sequence**

### stack(...values)

The given items are played at the same time at the same length:

<MiniRepl tune={`stack(g3, b3, [e4, d4])`} />

- Square Brackets will create a subsequence

### Nesting functions

You can nest functions inside one another:

<MiniRepl
  tune={`cat(
  stack(g3,b3,e4),
  stack(a3,c3,e4),
  stack(b3,d3,fs4),
  stack(b3,e4,g4)
)`}
/>

The above is equivalent to

<MiniRepl tune={`"<[g3,b3,e4] [a3,c3,e4] [b3,d3,f#4] [b3,e4,g4]>"`} />

### timeCat(...[weight,value])

Like with "@" in mini notation, we can specify weights to the items in a sequence:

<MiniRepl tune={`timeCat([3,e3],[1, g3])`} />

<!-- ## polymeter

how to use?

<MiniRepl tune={`polymeter(3, e3, g3, b3)`} /> -->

### polyrhythm(...[...values])

Plays the given items at the same time, within the same length:

<MiniRepl tune={`polyrhythm([e3, g3], [e4, g4, b4])`} />

We can write the same with **stack** and **cat**:

<MiniRepl tune={`stack(seq(e3, g3), seq(e4, g4, b4))`} />

You can also use the shorthand **pr** instead of **polyrhythm**.

## Time Modifiers

The following functions modify a pattern temporal structure in some way.

{{ 'Pattern.slow' | jsdoc }}

{{ 'Pattern.fast' | jsdoc }}

{{ 'Pattern.early' | jsdoc }}

{{ 'Pattern.late' | jsdoc }}

{{ 'Pattern.rev' | jsdoc }}

### struct(binary_pat)

Applies the given structure to the pattern:

<MiniRepl tune={`"c3,eb3,g3".struct("x ~ x ~ ~ x ~ x ~ ~ ~ x ~ x ~ ~").slow(4)`} />

This is also useful to sample signals:

<MiniRepl
  tune={`sine.struct("x ~ x ~ ~ x ~ x ~ ~ ~ x ~ x ~ ~").mul(7).round()
.scale('C minor').slow(4)`}
/>

## Conditional Modifiers

{{ 'Pattern.every' | jsdoc }}

{{ 'Pattern.each' | jsdoc }}

### when(binary_pat, func)

Applies the given function whenever the given pattern is in a true state.

<MiniRepl tune={`"c3 eb3 g3".when("<0 1>/2", sub(5))`} />

## Accumulation Modifiers

### stack(pat)

Stacks the given pattern to the current pattern:

<MiniRepl tune={`"c4,eb4,g4".stack("bb4,d5")`} />

### superimpose(...func)

Superimposes the result of the given function(s) on top of the original pattern:

<MiniRepl tune={`"<c3 eb3 g3>".scale('C minor').superimpose(scaleTranspose("2,4"))`} />

### layer(...func)

Layers the result of the given function(s) on top of each other. Like superimpose, but the original pattern is not part of the result.

<MiniRepl tune={`"<c3 eb3 g3>".scale('C minor').layer(scaleTranspose("0,2,4"))`} />

### off(time, func)

Applies the given function by the given time offset:

<MiniRepl tune={`"c3 eb3 g3".off(1/8, add(7))`} />

## Value Modifiers

### add(n)

Adds the given number to each item in the pattern:

<MiniRepl tune={`"0 2 4".add("<0 3 4 0>").scale('C major')`} />

Here, the triad `0, 2, 4` is shifted by different amounts. Without add, the equivalent would be:

<MiniRepl tune={`"<[0 2 4] [3 5 7] [4 6 8] [0 2 4]>".scale('C major')`} />

You can also use add with notes:

<MiniRepl tune={`"c3 e3 g3".add("<0 5 7 0>")`} />

Behind the scenes, the notes are converted to midi numbers as soon before add is applied, which is equivalent to:

<MiniRepl tune={`"48 52 55".add("<0 5 7 0>")`} />

### sub(n)

Like add, but the given numbers are subtracted:

<MiniRepl tune={`"0 2 4".sub("<0 1 2 3>").scale('C4 minor')`} />

See add for more information.

### mul(n)

Multiplies each number by the given factor:

<MiniRepl tune={`"0,1,2".mul("<2 3 4 3>").scale('C4 minor')`} />

... is equivalent to:

<MiniRepl tune={`"<[0,2,4] [0,3,6] [0,4,8] [0,3,6]>".scale('C4 minor')`} />

This function is really useful in combination with signals:

<MiniRepl tune={`sine.struct("x*16").mul(7).round().scale('C major')`} />

Here, we sample a sine wave 16 times, and multiply each sample by 7. This way, we let values oscillate between 0 and 7.

### div(n)

Like mul, but dividing by the given number.

### round()

Rounds all values to the nearest integer:

<MiniRepl tune={`"0.5 1.5 2.5".round().scale('C major')`} />

### apply(func)

Like layer, but with a single function:

<MiniRepl tune={`"<c3 eb3 g3>".scale('C minor').apply(scaleTranspose("0,2,4"))`} />

## Randomness

These methods add random behavior to your Patterns.

{{ 'chooseCycles' | jsdoc }}

{{ 'Pattern.degradeBy' | jsdoc }}

{{ 'Pattern.degrade' | jsdoc }}

{{ 'Pattern.undegradeBy' | jsdoc }}

{{ 'Pattern.sometimesBy' | jsdoc }}

{{ 'Pattern.sometimes' | jsdoc }}

{{ 'Pattern.someCyclesBy' | jsdoc }}

{{ 'Pattern.someCycles' | jsdoc }}

{{ 'Pattern.often' | jsdoc }}

{{ 'Pattern.rarely' | jsdoc }}

{{ 'Pattern.almostNever' | jsdoc }}

{{ 'Pattern.almostAlways' | jsdoc }}

{{ 'Pattern.never' | jsdoc }}

{{ 'Pattern.always' | jsdoc }}

{{ 'rand' | jsdoc }}

{{ 'perlin' | jsdoc }}

{{ 'irand' | jsdoc }}

## Tone API

To make the sounds more interesting, we can use Tone.js instruments ands effects.

[Show Source on Github](https://github.com/tidalcycles/strudel/blob/main/repl/src/tone.ts)

<MiniRepl
  tune={`stack(
    "[c5 c5 bb4 c5] [~ g4 ~ g4] [c5 f5 e5 c5] ~"
      .tone(synth(adsr(0,.1,0,0)).chain(out())),
    "[c2 c3]*8"
      .tone(synth({
        ...osc('sawtooth'),
        ...adsr(0,.1,0.4,0)
      }).chain(lowpass(300), out()))
  ).slow(4)`}
/>

### tone(instrument)

To change the instrument of a pattern, you can pass any [Tone.js Source](https://tonejs.github.io/docs/14.7.77/index.html) to .tone:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(new FMSynth().toDestination())`}
/>

While this works, it is a little bit verbose. To simplify things, all Tone Synths have a shortcut:

```js
const amsynth = (options) => new AMSynth(options);
const duosynth = (options) => new DuoSynth(options);
const fmsynth = (options) => new FMSynth(options);
const membrane = (options) => new MembraneSynth(options);
const metal = (options) => new MetalSynth(options);
const monosynth = (options) => new MonoSynth(options);
const noise = (options) => new NoiseSynth(options);
const pluck = (options) => new PluckSynth(options);
const polysynth = (options) => new PolySynth(options);
const synth = (options) => new Synth(options);
const sampler = (options, baseUrl?) => new Sampler(options); // promisified, see below
const players = (options, baseUrl?) => new Sampler(options); // promisified, see below
```

### sampler

With sampler, you can create tonal instruments from samples:

<MiniRepl
  tune={`sampler({
  C5: 'https://freesound.org/data/previews/536/536549_11935698-lq.mp3'
}).then(kalimba => 
  saw.struct("x*8").mul(16).round()
  .legato(4).scale('D dorian').slow(2)
  .tone(kalimba.toDestination())
)`}
/>

The sampler function promisifies [Tone.js Sampler](https://tonejs.github.io/docs/14.7.77/Sampler).

Note that this function currently only works with this promise notation, but in the future,
it will be possible to use async instruments in a synchronous fashion.

### players

With players, you can create sound banks:

<MiniRepl
  tune={`players({
    bd: 'samples/tidal/bd/BT0A0D0.wav',
    sn: 'samples/tidal/sn/ST0T0S3.wav',
    hh: 'samples/tidal/hh/000_hh3closedhh.wav'
  }, 'https://loophole-letters.vercel.app/')
  .then(drums=>
  "bd hh sn hh".tone(drums.toDestination())
)
  `}
/>

The sampler function promisifies [Tone.js Players](https://tonejs.github.io/docs/14.7.77/Players).

Note that this function currently only works with this promise notation, but in the future,
it will be possible to use async instruments in a synchronous fashion.

### out

Shortcut for Tone.Destination. Intended to be used with Tone's .chain:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(membrane().chain(out()))`}
/>

This alone is not really useful, so read on..

### vol(volume)

Helper that returns a Gain Node with the given volume. Intended to be used with Tone's .chain:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(noise().chain(vol(0.5), out()))`}
/>

### osc(type)

Helper to set the waveform of a synth, monosynth or polysynth:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(synth(osc('sawtooth4')).chain(out()))`}
/>

The base types are `sine`, `square`, `sawtooth`, `triangle`. You can also append a number between 1 and 32 to reduce the harmonic partials.

### lowpass(cutoff)

Helper that returns a Filter Node of type lowpass with the given cutoff. Intended to be used with Tone's .chain:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(synth(osc('sawtooth')).chain(lowpass(800), out()))`}
/>

### highpass(cutoff)

Helper that returns a Filter Node of type highpass with the given cutoff. Intended to be used with Tone's .chain:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(synth(osc('sawtooth')).chain(highpass(2000), out()))`}
/>

### adsr

Helper to set the envelope of a Tone.js instrument. Intended to be used with Tone's .set:

<MiniRepl
  tune={`"[c4 c4 bb3 c4] [~ g3 ~ g3] [c4 f4 e4 c4] ~".slow(4)
.tone(synth(adsr(0,.1,0,0)).chain(out()))`}
/>

## Tonal API

The Tonal API, uses [tonaljs](https://github.com/tonaljs/tonal) to provide helpers for musical operations.

### transpose(semitones)

Transposes all notes to the given number of semitones:

<MiniRepl tune={`"c2 c3".fast(2).transpose("<0 -2 5 3>".slow(2)).transpose(0)`} />

This method gets really exciting when we use it with a pattern as above.

Instead of numbers, scientific interval notation can be used as well:

<MiniRepl tune={`"c2 c3".fast(2).transpose("<1P -2M 4P 3m>".slow(2)).transpose(1)`} />

### scale(name)

Turns numbers into notes in the scale (zero indexed). Also sets scale for other scale operations, like scaleTranpose.

<MiniRepl
  tune={`"0 2 4 6 4 2"
.scale(seq('C2 major', 'C2 minor').slow(2))`}
/>

Note that the scale root is octaved here. You can also omit the octave, then index zero will default to octave 3.

All the available scale names can be found [here](https://github.com/tonaljs/tonal/blob/main/packages/scale-type/data.ts).

### scaleTranspose(steps)

Transposes notes inside the scale by the number of steps:

<MiniRepl
  tune={`"-8 [2,4,6]"
.scale('C4 bebop major')
.scaleTranspose("<0 -1 -2 -3 -4 -5 -6 -4>")`}
/>

### voicings(range?)

Turns chord symbols into voicings, using the smoothest voice leading possible:

<MiniRepl tune={`stack("<C^7 A7 Dm7 G7>".voicings(), "<C3 A2 D3 G2>")`} />

<!-- TODO: use voicing collection as first param + patternify. -->

### rootNotes(octave = 2)

Turns chord symbols into root notes of chords in given octave.

<MiniRepl tune={`"<C^7 A7b13 Dm7 G7>".rootNotes(3)`} />

Together with layer, struct and voicings, this can be used to create a basic backing track:

<MiniRepl
  tune={`"<C^7 A7b13 Dm7 G7>".layer(
  x => x.voicings(['d3','g4']).struct("~ x"),
  x => x.rootNotes(2).tone(synth(osc('sawtooth4')).chain(out()))
)`}
/>

<!-- TODO: use range instead of octave. -->
<!-- TODO: find out why composition does not work -->

## Microtonal API

TODO

## MIDI API

Strudel also supports midi via [webmidi](https://npmjs.com/package/webmidi).

### midi(outputName?)

Make sure to have a midi device connected or to use an IAC Driver.
If no outputName is given, it uses the first midi output it finds.

Midi is currently not supported by the mini repl used here, but you can [open the midi example in the repl](https://strudel.tidalcycles.org/#c3RhY2soIjxDXjcgQTcgRG03IEc3PiIubS52b2ljaW5ncygpLCAnPEMzIEEyIEQzIEcyPicubSkKICAubWlkaSgp).

In the REPL, you will se a log of the available MIDI devices.

<!--<MiniRepl
  tune={`stack("<C^7 A7 Dm7 G7>".voicings(), "<C3 A2 D3 G2>")
  .midi()`}
/>-->

# Contributing

Contributions of any sort are very welcome! You can contribute by editing [this file](https://github.com/tidalcycles/strudel/blob/main/repl/src/tutorial/tutorial.mdx).
All you need is a github account.

If you want to run the tutorial locally, you can clone the and run:

```sh
cd repl && npm i && npm run tutorial
```

If you want to contribute in another way, either

- [fork strudel repo on GitHub](https://github.com/tidalcycles/strudel)
- [Join the Discord Channel](https://discord.gg/remJ6gQA)
- [play with the Strudel REPL](https://strudel.tidalcycles.org/)

<br />
<br />

# API Docs

The following is generated from the source documentation.

## Pattern Factories

The following functions will return a pattern. We will see later what that means.

{{ 'pure' | jsdoc }}

{{ 'slowcat' | jsdoc }}

{{ 'fastcat' | jsdoc }}

{{ 'stack' | jsdoc }}

{{ 'timeCat' | jsdoc }}

{{ 'polyrhythm' | jsdoc }}

## Pattern Modifiers

{{ 'Pattern.slow' | jsdoc }}

{{ 'Pattern.fast' | jsdoc }}

{{ 'Pattern.early' | jsdoc }}

{{ 'Pattern.late' | jsdoc }}

{{ 'Pattern.rev' | jsdoc }}

{{ 'Pattern.legato' | jsdoc }}

## Continuous Signals

Signals are patterns with continuous values, meaning they have theoretically infinite steps.
They can provide streams of numbers that can be sampled at discrete points in time.

{{ 'Pattern.range' | jsdoc }}

{{ 'saw' | jsdoc }}

{{ 'saw2' | jsdoc }}

{{ 'sine' | jsdoc }}

{{ 'sine2' | jsdoc }}

{{ 'cosine' | jsdoc }}

{{ 'cosine2' | jsdoc }}

{{ 'tri' | jsdoc }}

{{ 'tri2' | jsdoc }}

{{ 'square' | jsdoc }}

{{ 'square2' | jsdoc }}

## Using Samples with Webdirt

You can use the powerful sampling engine [Webdirt](https://github.com/dktr0/WebDirt) with Strudel.

{{ 'Pattern.webdirt' | jsdoc }}

## Using Superdirt via OSC

In mainline tidal, the actual sound is generated via Superdirt, which runs inside Supercollider.
Strudel also supports using Superdirt as a backend, although it requires some developer tooling to run.

### Getting Started

Getting Superdirt to work with Strudel, you need to

1. install SuperCollider + sc3 plugins, see [Tidal Docs](https://tidalcycles.org/docs/) (Install Tidal) for more info.
2. install [node.js](https://nodejs.org/en/)
3. download [Strudel Repo](https://github.com/tidalcycles/strudel/) (or git clone, if you have git installed)
4. run `npm i` in the strudel directory
5. run `npm run osc` to start the osc server, which forwards OSC messages from Strudel REPL to SuperCollider

Now you're all set!

### Usage

1. Start SuperCollider, either using SuperCollider IDE or by running `sclang` in a terminal
2. Open the [Strudel REPL](https://strudel.tidalcycles.org/#cygiYmQgc2QiKS5vc2MoKQ%3D%3D)

...or test it here:

<MiniRepl tune={`s("bd sd").osc()`} />

If you now hear sound, congratulations! If not, you can get help on the [#strudel channel in the TidalCycles discord](https://discord.com/invite/HGEdXmRkzT).

{{ 'Pattern.osc' | jsdoc }}

# Superdirt Params

The following functions are specific to SuperDirt and won't work with other Strudel outputs.

## Basic Types

{{ 's' | jsdoc }}

{{ 'n' | jsdoc }}

{{ 'freq' | jsdoc }}

{{ 'channel' | jsdoc }}

{{ 'orbit' | jsdoc }}

## Filters

{{ 'cutoff' | jsdoc }}

{{ 'resonance' | jsdoc }}

{{ 'hcutoff' | jsdoc }}

{{ 'hresonance' | jsdoc }}

{{ 'bandf' | jsdoc }}

{{ 'bandq' | jsdoc }}

{{ 'djf' | jsdoc }}

{{ 'vowel' | jsdoc }}

## Sample Editing

{{ 'cut' | jsdoc }}

{{ 'begin' | jsdoc }}

{{ 'end' | jsdoc }}

{{ 'loop' | jsdoc }}

{{ 'fadeTime' | jsdoc }}

{{ 'speed' | jsdoc }}

{{ 'unit' | jsdoc }}

## Audio Effects

{{ 'gain' | jsdoc }}

{{ 'amp' | jsdoc }}

{{ 'accelerate' | jsdoc }}

{{ 'crush' | jsdoc }}

{{ 'coarse' | jsdoc }}

{{ 'delay' | jsdoc }}

{{ 'lock' | jsdoc }}

{{ 'leslie' | jsdoc }}

{{ 'lrate' | jsdoc }}

{{ 'lsize' | jsdoc }}

{{ 'pan' | jsdoc }}

{{ 'panspan' | jsdoc }}

{{ 'pansplay' | jsdoc }}

{{ 'room' | jsdoc }}

{{ 'size' | jsdoc }}

{{ 'dry' | jsdoc }}

{{ 'shape' | jsdoc }}

{{ 'squiz' | jsdoc }}

{{ 'waveloss' | jsdoc }}

{{ 'attack' | jsdoc }}

{{ 'decay' | jsdoc }}

## Synth Effects

{{ 'octave' | jsdoc }}

{{ 'detune' | jsdoc }}

{{ 'tremolodepth' | jsdoc }}