Start with the best source you have
Before you scan anything, check whether you already have a better file.
- Digital (born-digital) PDFs — exported from notation software such as MuseScore, Sibelius, Dorico or Finale, or sold by a publisher as a download — are drawn as perfectly sharp vector shapes. They are the best possible input for OMR.
- Scanned PDFs are photographs of paper inside a PDF wrapper. Their quality depends entirely on how they were scanned. Many free library scans are low-resolution or heavily compressed.
- Phone photos can work very well if you take care, but they add perspective, curvature and uneven light that a flatbed scanner avoids.
You can tell the difference by zooming in a long way on the PDF: a digital file stays crisp at any zoom, a scan becomes blocky or fuzzy.
Resolution: aim for about 300 DPI
For a flatbed scanner, 300 DPI (dots per inch) in greyscale is the sweet spot. It captures thin staff lines, stems, dots and small accidentals clearly while keeping files small. Below about 200 DPI, augmentation dots and staccato marks start to merge with staff lines; above 400 DPI, files get large without improving recognition. If the music is printed very small — pocket scores, condensed hymnals — 400 DPI can help.
For phone photos, resolution is rarely the problem; modern cameras capture plenty. What matters is that the page fills the frame so those pixels are spent on music, not on the table around it.
Colour, greyscale or black and white?
Greyscale is safest. Pure black-and-white (1-bit) modes and the "document" filters in scanning apps can thin out staff lines or fill in note heads, especially on faint copies. Colour works but makes files larger for no benefit.
Flat, straight and evenly lit
OMR finds staves by looking for groups of five parallel lines. Anything that bends or shadows those lines causes trouble.
- Flatten the page. Curvature near a book's spine is the most common cause of missed or garbled systems. Press the book gently onto the scanner glass, or for photos lay a sheet of clear glass or acrylic over the page.
- Shoot straight down. Hold the phone parallel to the page, centred over it. An angled shot makes the top of the page smaller than the bottom, and staff lines stop being parallel.
- Avoid shadows. Your hand and phone cast a shadow under overhead lights. Daylight from a window, or two lamps from either side, gives even light. Avoid flash, which creates a bright hotspot on glossy paper.
- Keep it level. Small rotations are corrected automatically, but a page that is badly skewed should be re-shot.
- Hold still and focus. Tap the screen to focus on the staff, and brace your elbows. Motion blur turns eighth-note flags into smudges.
Contrast and cropping
You want dark notes on a light background with nothing else in the picture. Crop away the desk, fingers and the facing page, but leave a small margin around the music so the first and last staff are not cut off — a clipped clef or time signature changes how the whole line is read. If a photocopy is faint, increase contrast slightly before uploading; do not push it so far that thin lines disappear.
One page per image, or one multi-page PDF?
An image file (PNG or JPG) is one page. For a piece longer than a page, it is usually better to combine the pages into a single PDF in the correct order, so the recognised score flows from one page to the next. Most phones can do this without extra apps: on an iPhone, the Notes and Files apps have a document scanner; on Android, the Google Drive app has a scan option. Choose greyscale rather than black-and-white in their settings if offered. If you scan pages separately, name the files in order (01, 02, 03…) so nothing ends up out of sequence.
File checklist: PDF, PNG or JPG; around 300 DPI for scans; the whole page in frame with a small margin; greyscale; under 50 MB, which is Musaica's upload limit. If your phone saves photos as HEIC, upload through the browser (which usually converts to JPG) or switch the camera to "Most Compatible".
What OMR commonly misreads — and what to do
Even a perfect scan will not make every symbol recognisable. These are the usual weak points for any OMR engine, including Audiveris, the open-source engine Musaica uses:
| Element | What goes wrong | What to do |
|---|---|---|
| Grace notes and ornaments | Small notes are skipped or read as full notes, adding beats | Accept that ornaments may be missing in playback; add them yourself when you play. |
| Clef changes mid-bar | The small clef is missed, so following notes are read in the wrong clef | Listen for a sudden jump in register; read those bars from the page. |
| Tuplets | The small 3 (or 5, 6…) is missed and the bar has too many beats | Scan at higher resolution; check bars with triplets by ear. |
| Lyrics | Usually dropped, sometimes misread as symbols | Keep the original for the words; the notes still play. |
| Chord symbols and guitar tab | Text above the staff is often ignored; tab staves may not be recognised | Use the standard notation staff for playback. |
| Handwritten music | Irregular shapes recognise poorly | Neat, dark, well-spaced handwriting works best; for important pieces, re-enter in notation software. |
| Dense orchestral pages | Many tiny staves; some are merged or lost | Scan individual parts where available, or scan at 400 DPI. |
| Slurs vs ties | A slur read as a tie (or the reverse) changes whether a note is replayed | Compare suspicious held notes with the page. |
If a page still recognises badly after a careful scan, try the next-best source: a different edition, the individual instrumental part, or a born-digital PDF. If you need a perfect score for printing or performance, import the result into notation software and correct it there.
Scanning for Musaica
Musaica is a free online sheet music reader: it accepts PDF, PNG and JPG files up to 50 MB, recognises the notation with Audiveris and plays it back in your browser. Everything in this guide applies directly. A quick way to judge a scan is to play the first few bars and compare them with the page — if the key, time signature and opening notes are right, the rest of the page is usually in good shape. See our pages on the sheet music scanner and turning images into sheet music for more.
How to photograph a page of sheet music
- Flatten the page. Lay it on a table or press the book open; use a sheet of clear glass or acrylic if the spine curves.
- Light it evenly. Use daylight or two lamps from the sides. Turn off the flash and keep your shadow off the page.
- Frame it straight on. Hold the phone parallel to the page so the music fills the frame with a small margin on every side.
- Focus and hold still. Tap to focus on a staff and brace your elbows to avoid blur.
- Check and upload. Zoom in to check that dots and flags are sharp, then upload the photo or a combined PDF to the sheet player.
Frequently asked questions
What DPI should I scan sheet music at?
300 DPI in greyscale is ideal for optical music recognition. Go up to 400 DPI for very small print; below 200 DPI, dots and thin lines start to be lost.
Can I just take a photo with my phone?
Yes. Phone photos work well if the page is flat, evenly lit, shot straight on and fills the frame. Curved pages near a book spine and shadows are the most common problems.
Is a PDF better than a photo?
A born-digital PDF exported from notation software is the best input. A scanned PDF is only as good as the scan. For multi-page pieces, combining pages into one PDF keeps them in order.
Can OMR read handwritten sheet music?
Sometimes, but much less reliably than printed music. Neat, dark, evenly spaced handwriting has the best chance; for important pieces, entering the music in notation software is more dependable.
Why are the lyrics missing after scanning?
Most OMR engines focus on notes and often drop lyrics and chord symbols. The notes still play; keep the original page for the words.