Pattern Syntax¶

Learn the mini notation language for writing patterns in r0astr.

Mini Notation Basics¶

r0astr uses Strudel's mini notation - a concise language for describing musical sequences.

Sequences¶

Space-separated sounds play one after another within a cycle:

s("bd sd bd sd")  // Four sounds spread across one cycle

Rests (Silence)¶

Use ~ to create silence:

s("bd ~ sd ~")  // Sound, silence, sound, silence

Multiplication¶

Repeat a sound multiple times with *:

s("bd*4")     // Bass drum 4 times per cycle
s("hh*8")     // Hi-hat 8 times per cycle
s("bd*2 sd")  // Two kicks, then one snare

Subdivision¶

Use [] to subdivide time - items inside share the parent's time slot:

s("bd [hh hh]")      // bd gets half, two hh share the other half
s("bd [sd sd sd]")   // bd gets half, three snares share the other half
s("[[bd bd] hh] sd") // Nested subdivision

Stacking (Layering)¶

Use , to play sounds simultaneously:

s("bd*4, ~ sd ~ sd")           // Kick pattern + snare pattern together
s("bd*4, ~ sd ~ sd, hh*8")     // Full drum kit layered

Alternation¶

Use <> to alternate between options each cycle:

s("<bd sd>")           // bd first cycle, sd second cycle
s("<bd sd cp>")        // Cycles through three sounds
note("<c3 e3 g3>")     // Cycles through three notes

Sound Sources¶

Samples with `s()`¶

Play built-in samples using s():

s("bd hh sd hh")       // Use sample names
s("bd:0 bd:1 bd:2")    // Different variations with :n

Common Sample Names:

Name	Sound
`bd`	Bass drum / Kick
`sd`	Snare drum
`hh`	Hi-hat
`oh`	Open hi-hat
`cp`	Clap
`rim`	Rimshot
`tom`	Tom
`ride`	Ride cymbal

Synths with `note()`¶

Generate tones using note() with note names:

note("c3 e3 g3")                    // Play notes
note("c3 e3 g3").s("sawtooth")      // Choose synth type
note("c3 e3 g3").s("triangle")      // Different synth

Synth Types:

Type	Sound
`sawtooth`	Bright, buzzy (good for bass)
`triangle`	Soft, flute-like
`square`	Hollow, video-game style
`sine`	Pure tone, smooth

Scales with `n()`¶

Use scale degrees instead of note names:

n("0 2 4 5").scale("C:major")       // C D E F
n("0 1 2 3").scale("C:minor")       // C D Eb F
n("0 2 4").scale("A3:minor")        // Am chord

Common Modifiers¶

Chain modifiers after your pattern to shape the sound:

Quick Reference¶

Modifier	Description	Range	Example
`.gain(n)`	Volume level	0-1	`.gain(0.5)`
`.lpf(hz)`	Low-pass filter cutoff	20-20000	`.lpf(800)`
`.hpf(hz)`	High-pass filter cutoff	20-20000	`.hpf(200)`
`.fast(n)`	Speed up pattern	0.5-8	`.fast(2)`
`.slow(n)`	Slow down pattern	0.5-8	`.slow(2)`
`.room(n)`	Reverb amount	0-1	`.room(0.5)`
`.delay(n)`	Delay amount	0-1	`.delay(0.25)`
`.pan(n)`	Stereo position	-1 to 1	`.pan(-0.5)`

Volume with `.gain()`¶

Control volume from 0 (silent) to 1 (full):

s("bd*4").gain(0.8)                // 80% volume
s("hh*8").gain(0.3)                // Quieter hi-hats

Filters with `.lpf()` and `.hpf()`¶

Low-pass filter removes high frequencies (makes sound duller):

note("c2").s("sawtooth").lpf(400)  // Dark bass
note("c2").s("sawtooth").lpf(2000) // Brighter bass

High-pass filter removes low frequencies (makes sound thinner):

s("bd*4").hpf(200)                 // Thin kick

Speed with `.fast()` and `.slow()`¶

Change pattern speed:

s("bd sd bd sd").fast(2)           // 2x speed (8 hits per cycle)
s("bd sd bd sd").slow(2)           // Half speed (takes 2 cycles)

Reverb with `.room()`¶

Add space and ambience:

note("c3 e3 g3").room(0.5)         // Medium reverb
note("c3 e3 g3").room(0.9)         // Large hall reverb

Sliders¶

Add interactive sliders to control values in real-time.

Basic Syntax¶

slider(default, min, max)

default: Starting value
min: Minimum value
max: Maximum value

Usage Example¶

note("c2 ~ c2 e2").s("sawtooth").lpf(slider(800, 100, 5000))

This creates a slider that: - Starts at 800 Hz - Can be adjusted from 100 Hz to 5000 Hz - Updates the filter in real-time as you drag

Multiple Sliders¶

Each slider appears in the card's control area:

note("c2 ~ c2 e2")
  .s("sawtooth")
  .lpf(slider(800, 100, 5000))
  .gain(slider(0.6, 0, 1))

Example Patterns¶

Copy-paste these into r0astr to try them.

Drums¶

Four on the Floor

s("bd*4, ~ sd ~ sd, hh*8").gain(0.8)

Rock Beat

s("bd ~ bd ~, ~ sd ~ sd, hh*8").gain(0.8)

Breakbeat

s("bd sd:1 [~ bd] sd:2, hh*8").fast(1).gain(0.7)

Bass¶

Sub Bass

note("c2 ~ c2 ~").s("sawtooth").lpf(200).gain(0.6)

Walking Bass

note("c2 e2 g2 e2").s("sawtooth").lpf(400).gain(0.5)

Synth Bass

note("c2 ~ c2 eb2, ~ ~ g2 ~").s("square").lpf(slider(300, 100, 1000)).gain(0.5)

Melody¶

Arpeggiated Chord

n("0 2 4 7").scale("C4:minor").s("triangle").gain(0.5)

Chord Stabs

n("[0,2,4] ~ [0,2,4] ~").scale("C4:minor").s("sawtooth").lpf(1200).gain(0.4)

Lead Line

n("0 2 3 5 3 2").scale("C5:minor").s("triangle").room(0.3).gain(0.5)

Ambient¶

Soft Pad

n("0 3 7").scale("C3:minor").s("sawtooth").lpf(600).room(0.8).slow(4).gain(0.4)

Shimmer

n("<0 2 4 5>").scale("C5:major").s("triangle").room(0.9).delay(0.3).slow(2).gain(0.3)

Combining Techniques¶

Build complex patterns by combining these techniques:

// Evolving bass with slider control
note("c2 ~ [c2 c2] eb2")
  .s("sawtooth")
  .lpf(slider(400, 100, 2000))
  .gain(0.6)
  .room(0.2)

// Layered percussion
s("bd*4, [~ sd]*2, [hh hh hh ~]*2")
  .gain(slider(0.7, 0, 1))

Next Steps¶

Practice: Copy patterns above and modify them
Experiment: Change numbers, add modifiers, break things
Explore: See Multi-Instrument Guide for using multiple cards

Full Reference¶

This guide covers the essentials. For the complete Strudel reference including all functions, patterns, and advanced techniques:

strudel.cc/learn