cecilia

A keyboard-first editor and player for guitar tab, standard notation and Gregorian chant. Open Guitar Pro files, play along with a recording, and edit square-note chant in a real WYSIWYG editor. Free and open source, written in Rust, with a window and a terminal interface.

[!WARNING] cecilia is still in development. Until version 1.0.0, features, key bindings, commands, config options and the native file formats (.ccc, .ccm) can change in breaking ways between releases. Keep your scores in a standard format too (Guitar Pro, MusicXML, GABC) and read the changelog before upgrading.

Why cecilia

• Chant is a first-class citizen. A WYSIWYG square-notation editor, not a text file and a typesetter: see below.
• Guitar Pro in, Guitar Pro out. Reads GP3–GP8 and writes GP5, GPX and GP7/8, so you are not locked in either direction.
• Play along with the real recording. Sync an mp3/flac/ogg/m4a to the score and practise with loops, speed and pitch control.
• Everything from the keyboard, vim-style, in the window and in the terminal, with the same key bindings in both.
• Free, open source, and scriptable from the command line (convert, engrave, inspect).

Features

Notation and engraving

• Guitar tablature, standard notation, slash notation, drums (standard drum notation and CY/HH/SN/BD drum tab) and piano grand staves; up to four voices per bar
• Lyrics with several verses, hyphenation and repeats; markers, sections and repeats (D.C./D.S.), tuplets, ties, and most Guitar Pro techniques (bends, slides, hammer-ons, harmonics, palm mute, …), auto-fingering and retuning
• Gregorian chant in square notation: neumes, clefs, divisions, custodes, episemata, morae, drop cap initial; equalist or Solesmes rhythm
• Page, continuous-vertical and continuous-horizontal layouts, zoom, split panes

Playback and practice

• MIDI playback with a moving cursor, through a SoundFont (.sf2) or a built-in synth
• Audio play-along: attach a recording (or use the one embedded in a GP7/8 file), sync it by tapping bars or with beat detection, and play it alone or mixed with the MIDI at any speed or pitch
• A–B loops, speed trainer, metronome and count-in; a waveform strip with sync points
• Fretboard and piano views that light up the notes at the cursor; a built-in tuner
• A tracks panel with volume, solo, mute and instrument per track

Editing

• Vim-style Normal / Insert / Visual modes, operators and counts, macros, marks and an undo tree
• Command line (:), command palette, pickers for files, buffers and workspaces, a which-key hint popup, mouse support
• Workspaces: views, pane splits and open files are remembered between sessions
• Themes (15 built-in presets, or your own) and TOML configuration with custom key bindings, reloaded as you save

Interfaces

• GUI: a GPU-rendered window (wgpu/vello) with engraved notation and click-to-place cursor
• TUI: a terminal interface with tablature view and basic editing, which also works over SSH

Files and export

• From the command line (cecilia convert): PDF, SVG and PNG export of engraved notation; WAV/FLAC export of the MIDI rendering mixed with the recording; MIDI, MusicXML and GABC output

Where cecilia fits

cecilia is young and pre-1.0. Its focus is chant and tab in one keyboard-driven tool, and practising with a recording from a terminal or a plain window. What it does and does not do today:

• Reads Guitar Pro 3-5 (.gp3-.gp5) and 6-8 (.gpx, .gp); writes GP5, GPX and GP7/8.
• Reads and writes MusicXML, MIDI and GABC (Gregorio), plus its own .ccc / .ccm files.
• Sounds: a SoundFont (.sf2) you provide, or a basic built-in synth. No SoundFont is bundled.
• Platforms: Linux is the tested platform. On macOS (Intel, in a virtual machine) and Windows (virtual machine) the terminal interface was run and builds from source; the window, audio and tuner were never run there (the VMs had no GPU and no sound device).
• Not there yet: binary releases, distribution packages, a plugin or scripting interface, and the polish and community of older programs such as Guitar Pro, MuseScore or TuxGuitar.

WYSIWYG chant editor

Most chant workflows mean writing GABC text and compiling it with a typesetter to see the result. cecilia edits the engraved chant directly: what you see on the page is the score you are editing.

• Square notation is drawn as you work, in the Caeciliae font: neumes, clefs, divisions, custodes, episemata, morae, liquescents, flats and the drop-cap initial
• Click to place the cursor on a note or syllable, move with the same keys as everywhere else, and change pitches, note shapes, clefs and divisions with a few keystrokes (tc3 for a do clef on line 3, td: for a division); a palette lists them for the mouse
• Edits are undoable, in an undo tree, and play back straight away
• Plain GABC stays the interchange format: open .gabc from GregoBase or Gregorio, and save .gabc back; :gabc edits the raw source when you want it
• Sync a chant to a recording by tapping syllable by syllable (automatic detection for chant is not done yet)
• Convert between modern notation and chant (:modern-to-chant, :chant-to-modern)
• Export square notation to PDF, SVG or PNG (cecilia convert chant.gabc chant.pdf)

In the terminal, chant is shown as a text staff (the engraved view needs the GUI). See docs/CHANT.md.

Installation

cecilia is not packaged yet: the repository has version tags only, no binary releases or distribution packages, so for now you build it from source. You need a Rust toolchain (1.88 or newer) and git.

git clone https://github.com/kjmcnamara1/cecilia.git && cd cecilia

Linux

Building needs a C compiler, pkg-config and the ALSA development files (the window system libraries are loaded at run time):

Then run the installer, which builds cecilia (in a release archive it installs the cecilia binary next to it instead) and adds a desktop entry, icon, licences and file types so file managers offer it for Guitar Pro, GABC and cecilia files:

packaging/linux/install.sh                   # into ~/.local (make sure ~/.local/bin is on PATH)
sudo packaging/linux/install.sh /usr/local   # system-wide
packaging/linux/uninstall.sh [PREFIX]        # remove it again

A Vulkan- or OpenGL-capable graphics driver is needed for the window (--gui).

macOS and Windows

Packaged builds do not exist yet, and these platforms are not tested by the author. In principle the same build works:

cargo install --locked --path crates/cecilia

This puts cecilia on your PATH (in ~/.cargo/bin). There is no installer, file association or desktop entry; run cecilia --gui song.gp5 from a terminal. Bug reports from these platforms are welcome. The terminal interface needs a modern terminal; on Windows use Windows Terminal.

Build requirements: on Windows the Visual Studio C++ Build Tools ("Desktop development with C++") and LLVM (the bindgen build step needs libclang; set LIBCLANG_PATH to LLVM's bin folder if it is not found). On macOS the Xcode command line tools (xcode-select --install). The window (--gui) needs a graphics driver with working compute shaders; on Windows it crashed inside Windows' software renderer on a virtual machine without 3D acceleration (see TODO.md). Setting CECILIA_CPU=1 makes the renderer run its shader stages on the CPU (slower, untested on that VM); on Linux VMs install a software Vulkan driver (mesa-vulkan-swrast / lavapipe) or use the terminal UI.

Terminal notes: the default tabline.icons = "nerd" needs a Nerd Font in the terminal; without one icons show as boxes, so run :set tabline.icons unicode (or none). Apple's Terminal.app only does 256 colors, so cecilia switches to the 256-color palette there; set CECILIA_COLORS=truecolor or 256 to override the detection. iTerm2 shows the full theme.

Just try it

cargo run --release -- --gui song.gp5

Usage

cecilia song.gp5            # open in the terminal UI
cecilia --gui song.gp5      # open in a window
cecilia                     # reopen your last workspace
cecilia -W practice a.gp5   # open files in a named workspace

The window needs --gui; without it you get the terminal UI. Command-line tools:

cecilia info song.gp5                                 # tracks, tunings, tempo, length (--json)
cecilia play song.gp5                                 # headless playback
cecilia convert in.gpx out.musicxml                   # convert; the output extension picks the format
cecilia convert song.gp5 song.pdf --track 2 --layout page   # engrave to PDF / SVG / PNG
cecilia convert song.gp song.flac                     # render MIDI + recording to audio
cecilia convert hymn.gp5 hymn.gabc                    # melody and lyrics as chant (lossy)
cecilia convert chant.gabc chant.pdf                  # square notation

First steps in the editor

Space is the leader key. Open a chant with cecilia chant.gabc --gui and use t followed by a letter for note shapes, clefs and divisions (see docs/keymap.md).

To practise with a recording: open the score, attach the audio file (:audio recording.mp3), tap the bars in Sync mode (S) or run :sync-detect, then play with Space Space; Space l loops the bars you select, Space - / Space = change the speed.

Configuration

On Linux, ~/.config/cecilia/config.toml ($XDG_CONFIG_HOME/cecilia/; other platforms use their standard config directory, or pass --config); see docs/config.example.toml for every option, and docs/keymap.md for key bindings (all can be overridden). For realistic instrument sounds set audio.soundfont to a General MIDI .sf2 file (for example FluidR3_GM or GeneralUser GS); otherwise the built-in synth is used.

Documentation

• docs/keymap.md: every key binding and command
• docs/CHANT.md: chant model and conversion
• docs/LYRICS.md: lyrics
• docs/SPEC.md: specification, file formats and roadmap
• CHANGELOG.md and TODO.md: what changed and what is planned

Contributing and development

cargo test --workspace
cargo clippy --workspace --all-targets -- -D warnings

Format tests also parse every Guitar Pro file under test-corpus/ (gitignored; point it at your own collection, e.g. ln -s ~/Music/Tabs test-corpus). Architecture notes for contributors are in AGENTS.md.

Fonts

Bundled under the SIL Open Font License 1.1 (texts in crates/cecilia-engrave/fonts/): Bravura (music symbols), Source Sans 3 (text), Noto Serif (the lyrics of chant scores by default, and the versicle, response, dagger and barred A in any font) and Caeciliae by the Oblates of St. Joseph (square chant notation).

License

Licensed under either of Apache License 2.0 or MIT at your option.