Lilylet

Lilylet is a LilyPond-like music notation language designed for Markdown rendering and symbolic music representation in AIGC applications.

Hello World

\key c \major \time 4/4 \clef "treble" c1 \bar "|."

A Comprehensive Example

[title "Jesu, meine Freude"]
[subtitle "BWV 610"]
[composer "J.S. Bach"]

\staff "1" \key c \minor \time 4/4 \clef "treble" \stemUp g'4 g f ef \\
\staff "1" \stemDown ef16[ d ef8]~ ef16[ f ef d] c8[ d]~ d[ c] \\
\staff "2" \clef "bass" c16[ b c8]~ c16[ b c g] a8[ g]~ g16[ g af ef] \\
\staff "3" \clef "bass" r8 c,16[ d] ef[ d ef8]~ ef16[ a, b g] c[ b c8] | % 1

\staff "1" \stemUp d2 c\fermata \\
\staff "1" \stemDown c8[ c4 b8] c8.[ \staff "2" \stemUp g16] \staff "1" c[ b c d] \\
\staff "2" f,16[ ef f d] g[ af g f] ef[ d ef8]~ ef16[ f ef d] \\
\staff "3" r16 g,[ af f] g[ f g8] c,2 | % 2

Try It Online

• Live Editor - Interactive editor with real-time music notation rendering
• Markdown Editor - Write documents with embedded Lilylet music snippets
• Tutorial - Comprehensive guide to Lilylet syntax

Why a New Language?

1. Leveraging LilyPond's Excellent Syntax

LilyPond uses a LaTeX-like text markup syntax with significant advantages:

• Beginner-friendly: Intuitive commands like \clef, \key, \time require no knowledge of complex binary formats
• Human-readable: Notes are represented directly as letters (c d e f g a b), durations as numbers (4 = quarter note)
• Relative pitch mode: Each note is calculated relative to the previous one—only octave shifts (' or ,) are needed when the interval exceeds a fourth, dramatically reducing octave markers. See LilyPond Relative Octave Entry

2. Reducing LilyPond's Excessive Flexibility

LilyPond is powerful but overly flexible—the same music can be written in multiple ways, which creates problems for AIGC scenarios:

| Issue | LilyPond | Lilylet | |-------|----------|---------| | Verbose context | Requires \version, \header, \paper, \layout boilerplate | Only core music content | | Inconsistent formats | Relative pitch, absolute pitch, multiple chord notations | Unified format, reduced ambiguity | | Complex nesting | \new Staff << \new Voice \relative c' { ... } >> | \staff "1" ... |

3. Optimized for AIGC

• Shorter context description: Removes redundant information, allowing LLMs to process more music content within limited context windows
• Formatted layout: Fixed syntax structure facilitates model learning and generation
• Markdown-embeddable: Music snippets can be directly embedded in documents