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Concepts

Understand the mental model behind r0astr to make the interface intuitive.

The Big Picture

r0astr is a multi-instrument live coding environment. Think of it as having four independent instruments on stage, all connected to the same metronome. You write code to control each instrument, and they all play together in perfect sync.

graph TB
    subgraph r0astr["r0astr Interface"]
        MP["🎛️ Master Panel<br/>TEMPO, Global Effects"]
        C1["📦 Card 1<br/>Drums"]
        C2["📦 Card 2<br/>Bass"]
        C3["📦 Card 3<br/>Melody"]
        C4["📦 Card 4<br/>Ambient"]
    end
    CLOCK(("🕐 Shared Clock"))
    MP --> CLOCK
    CLOCK --> C1
    CLOCK --> C2
    CLOCK --> C3
    CLOCK --> C4

Cards

Each card is an independent instrument in r0astr.

What is a Card?

A card is a self-contained unit that includes:

  • A code editor where you write patterns
  • A Play/Pause button to control playback
  • Slider controls for real-time parameter adjustments

Independence

Cards operate independently:

  • Different patterns: Each card can play completely different music
  • Separate controls: Start, stop, and modify each card without affecting others
  • Own parameters: Each card can have its own sliders and settings

Typical Setup

Most compositions use cards for different roles:

Card Common Use
Card 1 Drums and percussion
Card 2 Bass line
Card 3 Melody or lead
Card 4 Ambient or effects

This is just a suggestion - use cards however you like!

Learn more in the Multi-Instrument Guide

Synchronization

All cards share a single audio clock. This is the key to how r0astr works.

Shared Clock

  • Every card receives timing from the same master clock
  • When you start a new card, it automatically syncs with already-playing patterns
  • No drift or timing issues between instruments

What This Means in Practice

  1. Start Card 1 with a drum pattern
  2. Start Card 2 with a bass line - it immediately locks to the beat
  3. Start Card 3 with a melody - also perfectly in sync
  4. All three play together as if they were designed as one piece

Quantization

When you press Play on a card:

  • The pattern doesn't start immediately at a random point
  • It waits for the next cycle boundary
  • This ensures musical timing is always correct

Master Panel

The master panel sits above all cards and provides global controls.

Purpose

The master panel affects everything at once:

  • TEMPO: Set the speed (in CPS - cycles per second)
  • Global Sliders: Create variables like SLIDER_LPF that all cards can use
  • Master Effects: Apply filters or effects to the entire mix

TEMPO Control

The master panel is where you set the global tempo using a slider:

// In Master Panel
let TEMPO = slider(30, 15, 45);  // 30 CPS, range 15-45

All cards automatically follow this tempo.

Global Sliders

Define sliders in the master panel that any card can reference:

// Master Panel
let SLIDER_LPF = slider(800, 100, 5000);

// Card 1 (or any card) can use it:
s("bd*4").lpf(SLIDER_LPF)

This lets you control parameters across all instruments with a single slider.

Learn more in the Master Panel Guide

Pattern Lifecycle

Understanding how patterns work as you edit and play them.

The Flow

┌─────────┐     ┌─────────┐     ┌──────────────┐
│  Write  │ --> │  Play   │ --> │ Live Update  │
│ Pattern │     │         │     │  (optional)  │
└─────────┘     └─────────┘     └──────────────┘
                     │                  │
                     v                  v
                ┌─────────┐     ┌─────────┐
                │  Hear   │     │ Changes │
                │  Sound  │     │ Applied │
                └─────────┘     └─────────┘

Step by Step

  1. Write: Type or paste a pattern into a card's text area
  2. Play: Click the Play button to start the pattern
  3. Listen: Audio plays immediately through your speakers
  4. Edit (optional): Modify the pattern while it's playing
  5. Update: Changes take effect on the next cycle
  6. Pause: Click Pause to stop only that card

Live Coding

The magic of r0astr is live coding:

  • Edit patterns while they play
  • Hear changes almost instantly
  • No need to stop and restart
  • Experiment in real-time

Pro Tip

Make small changes and listen. This is the essence of live coding - evolving your music incrementally as you play.

How They Connect

Let's tie all the concepts together:

  1. You write patterns in each card using Strudel's mini notation
  2. Cards are independent - each runs its own pattern
  3. The master panel provides global controls like TEMPO
  4. A shared clock keeps everything synchronized
  5. Live updates let you evolve your music in real-time

Next Steps