Free online SMF to ABC converter

Some music-notation and folk-music tools require ABC text rather than a binary MIDI sequence. Converting an SMF file makes its notes, timing, key, and meter available for text editing, version control, printing, or sharing in ABC-compatible software.

What the SMF format is

SMF means Standard MIDI File. It is a binary file containing MIDI events such as note-on and note-off messages, instrument assignments, tempo changes, controller data, track names, and timing information; it contains performance instructions, not recorded sound.

SMF files usually use .mid, .midi, or occasionally .smf. Digital audio workstations, MIDI sequencers, notation programs, arranger keyboards, and electronic instruments create them. Type 0 files store all channels in one track, while Type 1 files separate synchronized parts into multiple tracks.

What the ABC format is

ABC is a plain-text music-notation format used extensively for melodies, folk tunes, lead sheets, and small traditional-music scores. An ABC file stores headers for fields such as title, composer, meter, unit note length, key, and tempo, followed by note letters, durations, rests, bar lines, accidentals, chords, and other notation symbols.

Because ABC is text, it can be edited with a normal text editor, compared in version-control systems, generated by scripts, and rendered by ABC notation software. It is usually much smaller than an SMF and is more suitable for representing readable notation, but it does not preserve every MIDI performance detail.

How to convert SMF to ABC

The most direct desktop method is midi2abc, part of the abcMIDI package.

1. Install abcMIDI for your operating system and place the SMF file in an accessible folder.
2. Run midi2abc input.mid -o output.abc in a terminal, replacing the filenames as required. If the input uses another extension, supply that filename instead.
3. Open output.abc in an ABC editor or renderer and check the inferred key, meter, tempo, bar lines, voices, and note lengths.
4. Edit the ABC headers and notation manually when the transcription needs musical correction, then save it as UTF-8 plain text with the .abc extension.

For a no-installation conversion, use the free converter on 101convert.com. Upload the SMF file, select ABC as the output format, start the conversion, and download the resulting ABC file. Review the generated notation before using it as an edition or score.

Quality and compatibility limitations

The converter must infer notation from MIDI timing. Quantization settings, pickup measures, swung rhythms, tempo changes, grace notes, tuplets, and human timing deviations can produce incorrect note lengths or bar divisions. A clean, quantized MIDI export generally converts better than a live performance recording.

MIDI channel and track structure may be mapped to ABC voices, but the result depends on the converter and the source file. Multiple instruments, dense chords, pedal data, pitch bends, modulation, patch changes, lyrics, and detailed articulation may be omitted or represented imperfectly. Drum channels do not normally translate into conventional pitched ABC notation.

SMF does not always contain an explicit key signature, and its tempo and meter events may change during the piece. Confirm the generated K:, M:, and Q: fields, and check ABC dialect compatibility if the target application expects a particular ABC version or rendering convention.