program for typesetting sheet music

 LilyPond is a music typesetter, an automated engraving system. It
 produces beautiful sheet music using a high level description file as input.
 .
 LilyPond supports many forms of music notation constructs, including
 chord names, drum notation, figured bass, grace notes, guitar tablature,
 modern notation (cluster notation and rhythmic grouping), tremolos,
 (nested) tuplets in arbitrary ratios, and more.
 .
 LilyPond's text-based music input language support can integrate into
 LaTeX, HTML and Texinfo seamlessly, allowing single sheet music
 or musicological treatises to be written from a single source. Form and
 content are separate, and with LilyPond's expert automated formatting,
 users don't need typographical expertise to produce good notation.
 .
 LilyPond produces PDF, PostScript, SVG, or TeX printed output, as well
 as MIDI for listening pleasures. LilyPond is exported from the
 RoseGarden and NoteEdit GUIs, and can import ABC, ETF and MIDI.
 .
 LilyPond is part of the GNU Project.