Free online OPUS to MUSICXML converter

An .opus file usually contains compressed audio, while .musicxml contains written musical notation. Converting between them therefore requires music transcription, not ordinary file-format conversion; a direct export is possible only when the OPUS file comes from notation software that supports MusicXML.

What the OPUS format is

.opus commonly identifies audio encoded with the Opus codec. Web browsers, voice-recording applications, messaging platforms, VoIP software, and FFmpeg create these files. They store sampled sound, not notes, rests, measures, key signatures, or articulations.

Some music and notation programs also use .opus as a proprietary project extension. The extension alone does not identify which format you have: inspect the file with the program that created it or use a media-information utility. An audio OPUS file will usually report Opus audio and a sample rate; a notation project will be recognized by its originating application.

What the MUSICXML format is

MusicXML is an XML-based interchange format for editable notation. It represents pitches, durations, voices, measures, clefs, key and time signatures, dynamics, lyrics, articulations, and much of a score’s layout.

Notation applications such as MuseScore, Sibelius, Dorico, and Finale can import or export MusicXML. It is suitable for moving a score between programs, editing individual notes, producing parts, and archiving notation in a documented, application-independent format. It does not store the original recording as audio.

How to actually convert OPUS to MUSICXML

If the OPUS file is an audio recording

1. Open the file in an audio editor or media player and confirm that it contains the performance you need to transcribe.
2. Optionally convert it to WAV for transcription software with FFmpeg:
   ffmpeg -i input.opus -ar 44100 -ac 2 input.wav
3. Use audio-to-MIDI transcription software that supports the material. Monophonic melodies are substantially easier to detect than piano, orchestral, or mixed recordings. Melodyne can export detected notes as MIDI; other transcription applications provide similar MIDI export.
4. Open the resulting .mid file in MuseScore with File → Open. Select the correct MIDI track, quantization, tempo interpretation, and instrument settings during import.
5. Correct the score manually: split or join measures, fix pitches and durations, assign voices, add rests, set the key and time signatures, and remove false notes.
6. Export the corrected score with File → Export, choose MusicXML, and save the result as output.musicxml.

Audiveris is useful for converting scanned sheet music or notation images to MusicXML, but it does not reliably transcribe ordinary audio. Audio-to-MusicXML conversion is therefore normally an audio-to-MIDI-to-MusicXML workflow.

If the OPUS file is a notation project

1. Open it in the application that created it; a file manager association or the file’s metadata can help identify that application.
2. Use the program’s native export command, such as File → Export → MusicXML. If MusicXML is unavailable, export MIDI first.
3. Open the exported MIDI in MuseScore, correct notation errors, then use File → Export and select MusicXML.

You can also try the free converter on 101convert.com, but it can convert the file only if its service recognizes the particular OPUS variant. An audio file cannot be transformed into accurate notation by a container-level conversion alone.

Quality and compatibility limitations

MusicXML export from an existing notation project generally preserves musical structure better than audio transcription. MIDI-to-MusicXML conversion can lose lyrics, page layout, instrument techniques, notation spacing, and ambiguous voice information.

Audio transcription may misidentify notes because of reverb, compression, overlapping instruments, vibrato, drums, tempo changes, and background noise. Expect manual editing, especially for chords and polyphonic passages. When importing MusicXML into another notation program, check tuplets, grace notes, repeats, linked parts, percussion mapping, and fonts because applications interpret optional MusicXML elements differently.