Samples

Samples are the most common way to make sound with tidal and strudel. A sample is a (commonly short) piece of audio that is used as a basis for sound generation, undergoing various transformations. Music that is based on samples can be thought of as a collage of sound. Read more about Sampling

Strudel allows loading samples in the form of audio files of various formats (wav, mp3, ogg) from any publicly available URL.

Default Samples

By default, strudel comes with a built-in “sample map”, providing a solid base to play with.

s("bd sd [~ bd] sd,hh*16, misc")

Here, we are using the s function to play back different default samples (bd, sd, hh and misc) to get a drum beat.

For drum sounds, strudel uses the comprehensive tidal-drum-machines library, with the following naming convention:

More percussive sounds:

Furthermore, strudel also loads instrument samples from VCSL by default.

To see which sample names are available, open the sounds tab in the REPL.

Note that only the sample maps (mapping names to URLs) are loaded initially, while the audio samples themselves are not loaded until they are actually played. This behaviour of loading things only when they are needed is also called lazy loading. While it saves resources, it can also lead to sounds not being audible the first time they are triggered, because the sound is still loading. This might be fixed in the future

Sound Banks

If we open the sounds tab and then drum machines, we can see that the drum samples are all prefixed with drum machine names: RolandTR808_bd, RolandTR808_sd, RolandTR808_hh etc..

We could use them like this:

s("RolandTR808_bd RolandTR808_sd,RolandTR808_hh*16")

… but thats obviously a bit much to write. Using the bank function, we can shorten this to:

s("bd sd,hh*16").bank("RolandTR808")

You could even pattern the bank to switch between different drum machines:

s("bd sd,hh*16").bank("<RolandTR808 RolandTR909>")

Behind the scenes, bank will just prepend the drum machine name to the sample name with _ to get the full name. This of course only works because the name after _ (bd, sd etc..) is standardized. Also note that some banks won’t have samples for all sounds!

Selecting Sounds

If we open the sounds tab again, followed by tab drum machines, there is also a number behind each name, indicating how many individual samples are available. For example RolandTR909_hh(4) means there are 4 samples of a TR909 hihat available. By default, s will play the first sample, but we can select the other ones using n, starting from 0:

s("hh*8").bank("RolandTR909").n("0 1 2 3")

Numbers that are too high will just wrap around to the beginning

s("hh*8").bank("RolandTR909").n("0 1 2 3 4 5 6 7")

Here, 0-3 will play the same sounds as 4-7, because RolandTR909_hh only has 4 sounds.

Selecting sounds also works inside the mini notation, using ”:” like this:

s("bd*4,hh:0 hh:1 hh:2 hh:3 hh:4 hh:5 hh:6 hh:7")
.bank("RolandTR909")

Loading Custom Samples

You can load a non-standard sample map using the samples function.

Loading samples from file URLs

In this example we assign names bassdrum, hihat and snaredrum to specific audio files on a server:

samples({
  bassdrum: 'bd/BT0AADA.wav',
  hihat: 'hh27/000_hh27closedhh.wav',
  snaredrum: ['sd/rytm-01-classic.wav', 'sd/rytm-00-hard.wav'],
}, 'https://raw.githubusercontent.com/tidalcycles/Dirt-Samples/master/');
 
s("bassdrum snaredrum:0 bassdrum snaredrum:1, hihat*16")

You can freely choose any combination of letters for each sample name. It is even possible to override the default sounds. The names you pick will be made available in the s function. Make sure that the URL and each sample path form a correct URL!

In the above example, bassdrum will load:

https://raw.githubusercontent.com/tidalcycles/Dirt-Samples/master/bd/BT0AADA.wav
|----------------------base path --------------------------------|--sample path-|

Note that we can either load a single file, like for bassdrum and hihat, or a list of files like for snaredrum! As soon as you run the code, your chosen sample names will be listed in sounds -> user.

Loading Samples from a strudel.json file

The above way to load samples might be tedious to write out / copy paste each time you write a new pattern. To avoid that, you can simply pass a URL to a strudel.json file somewhere on the internet:

samples('https://raw.githubusercontent.com/tidalcycles/Dirt-Samples/master/strudel.json')
s("bd sd bd sd,hh*16")

The file is expected to define a sample map using JSON, in the same format as described above. Additionally, the base path can be defined with the _base key. The last section could be written as:

{
  "_base": "https://raw.githubusercontent.com/tidalcycles/Dirt-Samples/master/",
  "bassdrum": "bd/BT0AADA.wav",
  "snaredrum": "sd/rytm-01-classic.wav",
  "hihat": "hh27/000_hh27closedhh.wav"
}

Github Shortcut

Because loading samples from github is common, there is a shortcut:

samples('github:tidalcycles/dirt-samples')
s("bd sd bd sd,hh*16")

The format is samples('github:<user>/<repo>/<branch>'). If you omit branch (like above), the main branch will be used. It assumes a strudel.json file to be present at the root of the repository:

https://raw.githubusercontent.com/<user>/<repo>/<branch>/strudel.json

From Disk via “Import Sounds”

If you don’t want to upload your samples to the internet, you can also load them from your local disk. Go to the sounds tab in the REPL and press “import sounds”. Then you can select a folder that contains audio files. The folder you select can also contain subfolders with audio files. Example:

└─ samples
   ├─ swoop
   │  ├─ swoopshort.wav
   │  ├─ swooplong.wav
   │  └─ swooptight.wav
   └─ smash
      ├─ smashhigh.wav
      ├─ smashlow.wav
      └─ smashmiddle.wav

In the above example the folder samples contains 2 subfolders swoop and smash, which contain audio files. If you select that samples folder, the user tab (next to the import sounds button) will then contain 2 new sounds: swoop(3) smash(3) The individual samples can the be played normally like s("swoop:0 swoop:1 smash:2").

From Disk via @strudel/sampler

Instead of loading your samples into your browser with the “import sounds” button, you can also serve the samples from a local file server. The easiest way to do this is using @strudel/sampler:

cd samples
npx @strudel/sampler

Then you can load it via:

samples('http://localhost:5432/');
 
n("<0 1 2>").s("swoop smash")

The handy thing about @strudel/sampler is that it auto-generates the strudel.json file based on your folder structure. You can see what it generated by going to http://localhost:5432 with your browser.

Note: You need NodeJS installed on your system for this to work.

Specifying Pitch

To make sure your samples are in tune when playing them with note, you can specify a base pitch like this:

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

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

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');
note("g2!2 <bb2 c3>!2, <c4@3 [<eb4 bb3> g4 f4]>")
  .s('moog').clip(1)
  .gain(.5).cpm(60)

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

Note that this notation for pitched sounds also works inside a strudel.json file.

Shabda

If you don’t want to select samples by hand, there is also the wonderful tool called shabda. With it, you can enter any sample name(s) to query from freesound.org. Example:

samples('shabda:bass:4,hihat:4,rimshot:2')
stack(
  n("0 1 2 3 0 1 2 3").s('bass'),
  n("0 1*2 2 3*2").s('hihat'),
  n("~ 0 ~ 1 ~ 0 0 1").s('rimshot')
).clip(1)

You can also generate artificial voice samples with any text, in multiple languages. Note that the language code and the gender parameters are optional and default to en-GB and f

samples('shabda/speech:the_drum,forever')
samples('shabda/speech/fr-FR/m:magnifique')
stack(
  s("the_drum*2").chop(16).speed(rand.range(0.85,1.1)),
  s("forever magnifique").slow(4).late(0.125)
)

Sampler Effects

Sampler effects are functions that can be used to change the behaviour of sample playback.

begin

samples({ rave: 'rave/AREUREADY.wav' }, 'github:tidalcycles/dirt-samples')
s("rave").begin("<0 .25 .5 .75>").fast(2)

end

s("bd*2,oh*4").end("<.1 .2 .5 1>").fast(2)

loop

s("casio").loop(1)

loopBegin

s("space").loop(1)
.loopBegin("<0 .125 .25>").scope()

loopEnd

s("space").loop(1)
.loopEnd("<1 .75 .5 .25>").scope()

cut

s("[oh hh]*4").cut(1)

clip

note("c a f e").s("piano").clip("<.5 1 2>")

loopAt

samples({ rhodes: 'https://cdn.freesound.org/previews/132/132051_316502-lq.mp3' })
s("rhodes").loopAt(2)

fit

samples({ rhodes: 'https://cdn.freesound.org/previews/132/132051_316502-lq.mp3' })
s("rhodes/2").fit()

chop

samples({ rhodes: 'https://cdn.freesound.org/previews/132/132051_316502-lq.mp3' })
s("rhodes")
 .chop(4)
 .rev() // reverse order of chops
 .loopAt(2) // fit sample into 2 cycles

striate

s("numbers:0 numbers:1 numbers:2").striate(6).slow(3)

slice

samples('github:tidalcycles/dirt-samples')
s("breaks165").slice(8, "0 1 <2 2*2> 3 [4 0] 5 6 7".every(3, rev)).slow(0.75)

samples('github:tidalcycles/dirt-samples')
s("breaks125").fit().slice([0,.25,.5,.75], "0 1 1 <2 3>")

splice

samples('github:tidalcycles/dirt-samples')
s("breaks165")
.splice(8,  "0 1 [2 3 0]@2 3 0@2 7")

speed

s("bd*6").speed("1 2 4 1 -2 -4")

speed("1 1.5*2 [2 1.1]").s("piano").clip(1)

After samples, let’s see what Synths afford us.