"My pieces" (/pieces) is your local piece library — this is where you import your own MusicXML/MXL files, and where you launch them into the player.
Drag the file into the drop zone
On /pieces, drag a .musicxml, .xml or .mxl file into the "Drop MusicXML here — or click" drop zone — or click it and choose the file from the dialog. On iPad, use "Open in Klavissimo" from the Files app.
Check the import before it counts
"Check import" then shows the sheet music, title, tempo and an estimated level, plus warnings for over-/underfilled bars. You can adjust the title, tempo and level right here. Only "Apply" actually adds the piece — "Discard" cancels without a trace.
If the import fails
"I can't read this file" opens with the reason: for a PDF, the note "A PDF is a picture of notes — not note data"; for other files, a tip to export it as MusicXML in MuseScore or check the "Where do I get sheet music?" help article instead. Nothing is ever saved in either case.
Rename, adjust the level, delete
"Estimate level" on the piece card sets the level automatically — or adjust it manually during the check step, which locks nothing. To delete, tap the ✕ in the top-right corner of the card; a confirmation prompt follows.
Your data:
The whole import stays on your device — nothing gets uploaded to Klavissimo. Pieces live in local browser storage and stay there until you delete them yourself; taking them to another device works via "Backup", or automatically via device sync (Plus) once it's set up.
Good to know:
No file of your own handy? Ten vetted, public-domain sources are listed in the "Where do I get sheet music?" help article — some of them importable straight away as MusicXML/MXL.