How to Convert Sheet Music Scans to MIDI [LEGATO AI · Free]

Convert Sheet Music to MIDI — Right in Your Browser, No Software Required

"I want to bring old sheet music into my DAW." "I'd love to digitize my handwritten scores and edit them in a piano roll." If you've searched for sheet music scanning and MIDI conversion, what you really want is a quick, concrete way to turn sheet music into MIDI data without buying dedicated software. In this guide, we'll break down how browser-based OMR (Optical Music Recognition) technology works and walk you through every step of the conversion process.

Understanding How Sheet Music Scanning and MIDI Conversion Works

The process of automatically generating MIDI data from a sheet music image is called OMR (Optical Music Recognition). Think of it as the musical equivalent of OCR (Optical Character Recognition) used for text documents.

Here's a simplified overview of how OMR works:

1. Image preprocessing: Noise reduction, skew correction, and binarization of the scanned image
2. Staff line detection: Identifying horizontal line patterns to isolate each system
3. Symbol classification: Recognizing note values (whole, dotted half, eighth, etc.), rests, accidentals, and time signatures
4. Pitch and duration assignment: Determining pitch and note length from staff position, flags, and accidentals
5. MIDI event generation: Converting pitch, duration, and tempo data into MIDI note-on/note-off events

Not long ago, this required dedicated applications like MuseScore, Finale, or SharpEye. Thanks to advances in AI and neural network-based recognition, however, browser-based tools can now deliver practical, real-world results.

What Is LEGATO AI? A Browser-Based Sheet Music OCR and MIDI Converter

LEGATO AI is an AI engine that automatically generates MIDI regions from uploaded sheet music images. Its biggest advantage is that it runs entirely in your browser — no installation needed — and works identically on Windows, Mac, and Chromebook.

Here's what it supports:

• Input formats: PNG / JPEG / PDF (sheet music scans)
• Recognized content: Printed scores and digital score screenshots (handwritten scores may yield lower accuracy)
• Output: MIDI regions placed directly on the DAW timeline for piano roll editing
• Supported symbols: Notes (whole, half, quarter, eighth, sixteenth), dotted notes, accidentals, rests, and basic repeat signs

LEGATO AI is built into the LA Studio editor, so you can go from conversion straight into piano roll editing and mixing without leaving the app. Heavy AI processing is available under the credit-based Pro plan.

Step-by-Step: Converting a Sheet Music Scan to MIDI

Step 1: Prepare Your Sheet Music Image

To get the best recognition results, keep the following in mind when preparing your image:

• Aim for 300 dpi or higher. If shooting with a smartphone, use the highest quality setting available.
• Shoot directly overhead so the full page fits in frame and distortion is minimized.
• Avoid shadows and creases falling across the staff lines.
• For multi-page scores, PDF format is the most convenient option.

If you don't have a scanner, a smartphone scanning app like Adobe Scan or Microsoft Lens works great — both apply automatic perspective correction and cropping.

Step 2: Open the LA Studio Editor

Navigate to https://la-studio.cc/editor in your browser. No account registration is required — the DAW launches the moment you open the page.

Step 3: Launch the Sheet Music OCR (LEGATO AI) Feature

1. Click the LA Menu at the top of the editor.
2. Select "Sheet Music OCR → MIDI (LEGATO AI)" from the menu.
3. A file dialog will appear — upload your sheet music image (PNG, JPEG, or PDF).
4. You can also drag and drop the file directly.

Step 4: Wait for AI Processing

Once uploaded, LEGATO AI analyzes the score. Processing typically takes around 10–30 seconds per letter/A4-sized page (depending on server load), after which MIDI regions are automatically placed on the editor timeline.

Step 5: Review and Edit in the Piano Roll

Double-click a converted MIDI region to open the piano roll. If the AI made any mistakes — such as missing accidentals or slightly off note durations — click the notes to correct them manually.

• Drag a note: Change its pitch or position
• Drag a note's edge: Change its duration
• Right-click: Delete or copy

Step 6: Export as a MIDI File

Once you're happy with the edits, go to the LA Menu and select "Export" to save the file as a standard MIDI (.mid). You can import it directly into any DAW — Cubase, Studio One, GarageBand, and more.

5 Tips for Better Recognition Accuracy

OMR isn't perfect — accuracy depends on image quality and score complexity. These tips can dramatically reduce recognition errors.

Tip 1: Use a Digital PDF from Notation Software

A PDF exported directly from notation software like MuseScore or Finale will always outperform a scanned image. Skipping the print-then-scan step means zero noise, giving the AI the cleanest possible input.

Tip 2: Work with Fewer Parts at a Time

Single-melody lines and piano grand staves (two staves) are much easier to recognize than dense orchestral scores. If your score has multiple parts, crop or split them by instrument and upload each one separately.

Tip 3: Straighten the Image

Tilted staff lines significantly reduce recognition rates. While you can rotate images in Windows Paint or Mac Preview, running the file through a dedicated tool like Adobe Acrobat or the free iLovePDF for automatic skew correction is more reliable.

Tip 4: Boost Contrast and Convert to Black and White

For grayscale scans or lightly printed scores, crank the contrast to maximum in any image editor before uploading. Sharper note edges mean better recognition.

Tip 5: Plan to Manually Enter Complex Ornaments

Trills, glissandos, crescendo markings, and similar expressive notation don't map cleanly to MIDI data, so OMR typically ignores or misreads them. Enter these by hand in the piano roll, or use velocity changes to approximate the musical intent.

LEGATO AI vs. Other Sheet Music to MIDI Tools

Several tools can handle sheet music scanning and MIDI conversion. Here's how they compare:

• MuseScore (Free): The go-to notation editor. Excellent at MusicXML import and MIDI export from scores you've created, but it doesn't natively read scanned images.
• Audiveris (Open Source): A dedicated OMR tool with solid accuracy, but it requires a Java installation and some technical setup to get running.
• PlayScore 2 (Paid App): Point your phone's camera at sheet music and get instant playback and MIDI output. Very user-friendly, but requires a paid subscription or one-time purchase.
• LEGATO AI (Browser · Integrated with LA Studio): No installation, and conversion flows directly into a full DAW environment. The tightest integration with a music production workflow.

If production efficiency matters to you, LEGATO AI's all-in-one environment — from scan conversion to piano roll editing to mixing, all in a single browser tab — is hard to beat.

Creative Uses: What You Can Do with Digitized Sheet Music in Your DAW

Arranging and Reharmonizing Classical Music

Scanning public-domain classical scores (Bach, Beethoven, Chopin, etc.) and converting them to MIDI is hugely popular among producers. Once you have the MIDI data, swapping in modern virtual instruments or rewriting the harmony is as simple as a few clicks.

Creating Practice Backing Tracks for Music Education

Scan the accompaniment part from a method book, convert it to MIDI, and slow down the tempo for a custom slow-practice backing track. Great for music teachers and students alike.

Breaking Down Band Scores by Instrument

Scan each instrument's part from a band score, convert to MIDI, and load them as separate tracks in your DAW. Perfect for checking rhythm parts or using them as a reference when programming drums and bass.

Combining with Voice to MIDI

LA Studio also includes a Voice to MIDI feature that converts singing or humming directly into MIDI notes. You can hum a melody, convert it to MIDI, and layer it over an accompaniment you scanned from sheet music — a seamless songwriting workflow.

Frequently Asked Questions

Q. Can I convert handwritten sheet music?

A. It's possible in some cases, but accuracy drops significantly compared to printed scores. Handwriting tends to have inconsistent note shapes and wobbly lines, making it harder for the AI to correctly identify note types and positions. For handwritten scores, a more practical approach is to transcribe them cleanly in MuseScore, export as PDF, and use that file instead.

Q. Can I use a photo taken with my smartphone?

A. Yes, but for best results: shoot directly overhead, ensure good lighting, and use the highest resolution setting. Using a scanning app like Adobe Scan or Microsoft Lens is even better — both apply automatic perspective correction and sharpening that noticeably improves recognition accuracy.

Q. Can I use the exported MIDI in GarageBand or Cubase?

A. Absolutely. MIDI files exported from LA Studio use the standard SMF (Standard MIDI File) format, which is compatible with GarageBand, Cubase, Studio One, Ableton Live, FL Studio, and virtually every other major DAW.

Q. Are there limits on the number of pages or notes I can convert?

A. LEGATO AI operates on a credit-based Pro plan, and credits are consumed based on the amount of processing. For current limits per upload and credit costs, check the pricing page on the LA Studio website. Small test conversions are available within the free tier.

Q. Can it handle polyphonic scores with multiple voices?

A. Standard multi-voice formats like a piano grand staff (treble and bass clef) are supported. That said, the more voices present, the more complex the recognition becomes and the more errors you may see. For orchestral scores with ten or more staves, splitting the score by instrument and uploading each part separately will give you better accuracy and a more manageable editing workflow.

Conclusion: Sheet Music Digitization Now Happens Entirely in the Browser

Not long ago, converting sheet music scans to MIDI meant purchasing dedicated software and wrestling with complex setup. Today, the entire pipeline — OMR processing, MIDI conversion, piano roll editing, and export — is available in a single browser tab, with no installation required.

LA Studio with LEGATO AI takes you from a scanned image all the way to a finished arrangement without switching apps or tabs. Whether you're digitizing an old score, arranging a classical piece, or building educational materials, give it a try and see how much faster your workflow can be.