Convert NoteWorthy Composer scores to MusicXML

Music::NWC2MusicXML reads a NoteWorthy Composer 2 .nwc file, still compressed in its binary container, and writes a MusicXML file that MuseScore, Finale, Sibelius and Dorico can open. NoteWorthy Composer itself does not have to be installed.

• Perl 5.36+
• GPL-2
• NWC 2.x
• MusicXML 4.0
• No NWC licence needed

cpanm Music::NWC2MusicXML

nwc2musicxml Pilgrim.nwc
# writes Pilgrim.musicxml beside it

The work is done in three stages that each stand on their own: the binary container is decompressed back to the text format NoteWorthy Composer uses, that text is parsed into a score of staves and events, and the score is written out as MusicXML 4.0. Every stage can be called directly, and a failure is reported with the code of the stage it came from rather than as one anonymous error.

• The container, not an export

  The NWC 2.x file is checked against its magic signature and inflated with zlib, so nothing has to be exported by hand and the converting machine needs no NoteWorthy Composer copy.

• Exact durations

  Rhythm is held as a rational in quarter-note units, and <divisions> is the least common multiple across every staff, so triplets, double dots and dotted triplets do not drift.

• Notation, not appearance

  Clefs, key and time signatures, tempo, dynamics, hairpins, fermatas, slurs, ties, grace notes, articulations, lyrics and barline styles come out as MusicXML elements.

• Dynamics that still sound

  A staff's NWC DynVel velocities become <sound dynamics="…"/>, so a playback engine can still tell mp from mf.

• Folders, not just files

  A directory argument collects the .nwc files in it; --recursive walks the tree and keeps its shape under --output-dir. One unreadable file does not abandon the rest.

• Diagnostics with codes

  error_no_input, error_decode, error_parse, error_generate and the rest are catalogue entries, so a script can act on them and --warnings can collect them in a file.

How a file is converted

1. Decode. Music::NWC2MusicXML::NWC->read verifies the magic signature, inflates the zlib payload and returns the pipe-delimited NWCTXT text the file was built from.
2. Parse. Music::NWC2MusicXML::Parser->parse walks the |RecordType|Field:Value records and builds a Score of Staff and Event objects, each event carrying its own duration and data.
3. Annotate. Slurs, ties, fermatas, wedges and bar-scoped accidentals are resolved across the whole event stream before measures are grouped, because each of them spans more than one note.
4. Generate. Music::NWC2MusicXML::MusicXML->generate writes the part list, measures, attributes, directions and notations, and hands back the document as a UTF-8 string.
5. Report. The diagnostics object counts what went wrong; the command line turns that into an exit status, so a shell script can tell a warning from a failure.

# one file
nwc2musicxml Pilgrim.nwc

# a folder tree, keeping its shape
nwc2musicxml --recursive --output-dir musicxml scores/

# the same thing from Perl
my $converter = Music::NWC2MusicXML->new;
my $out = $converter->convert(input => 'Pilgrim.nwc', overwrite => 1);

What it does not do

Tuplet notation is not emitted yet: the durations are exact, but the <time-modification> and <tuplet> elements that make a score print them as triplets are missing. A staff's simultaneous voices are all written to voice 1, the page is fixed to A4, and the lyric and flow-control paths have not been validated against a golden score. The whole list is here.

Where to go next

• Install — from CPAN or from a checkout, and what has to be present first.
• Quick start — one file to MuseScore, then a whole folder.
• Commands — the options, the exit codes and what counts as input.
• Perl API — convert, batch_convert and the three stages underneath.
• What converts — every NWC construct that has a MusicXML destination.