The Library is piano music that is out of copyright. Most modern songs are not in it, and cannot be. You can still bring one in yourself — here is the route, and its honest limits.
OmniPiano can take a score in two quite different shapes, and the difference decides how well practice works afterwards.
.mxl or .musicxml — the score as data rather than as a picture. Every note is written down: its pitch, how long it lasts, which hand plays it, which bar it is in.
Nothing has to be guessed, so nothing is guessed wrong.
A picture of the page. Before the app can do anything with it, the notes have to be read back off the image — the same kind of job as reading text off a scan.
It works, and it is usually good. It is not always right.
Why the difference matters more here than in an ordinary sheet-music player: in a player, one misread note sounds slightly wrong and you shrug. In wait mode the app stops and waits for you to play that note — and if the note is not in the music, you cannot play it. A file that already contains the notes removes that whole class of problem.
MuseScore.com is where these files are. It is a community of people who engrave music in MuseScore and share it, and a shared score can usually be downloaded as MusicXML.
Bach, Chopin, Debussy, Satie and the rest: free to download. Much of it is already in the OmniPiano Library, so it is worth looking there first — the Library versions come with the four practice levels already made.
These exist on MuseScore as community uploads, and downloading the file needs MuseScore's paid Pro subscription. That is their arrangement with the rights holders, not ours.
We earn nothing from this. No affiliate link, no commission, no agreement of any kind. We point at MuseScore because it is the only route we know of that ends in a file this app can read exactly.
MuseScore has two sorts of score. Community uploads can be downloaded as MusicXML. The Official Scores — the publisher editions — cannot, even with Pro; those end in a printable PDF. Look for the download menu and the MusicXML option; if it isn't there, the file isn't one you can bring.
Other sheet-music shops sell official editions as PDFs or in their own private formats. Those are fine to buy and print, and they are worth buying if you want the publisher's engraving on your music stand — but a PDF comes into the app the long way round, through recognition.
Bring it anyway. The app reads the notes off the page, rebuilds the score, and makes the practice levels from what it read. For a clean, printed page this often works well.
It can also be wrong: a pitch off by a step, a missing accidental, a voice put on the wrong staff. So:
A MIDI file is a third case. The app can play one, but it cannot build the practice levels from it yet: a MIDI has no staves and no hands, and every level is built from what each hand has to do. For levels, bring MusicXML or a page.
The Library is music whose copyright has expired. Nobody's permission is needed to hand it to you, which is why it is there and why it is free.
A song still in copyright is a different matter. To give you the notes we would need a licence from the publisher, and we don't have one — so we don't, for any song, however often it is asked for.
Working on a file you already have is not the same thing as handing it out. An import belongs to your account and is not added to the Library; it is your copy, for your own practice. That is why the route runs through a source that is licensed to give you the file in the first place.
.mxl or .musicxml). A PDF or a photo of the page will also do; see above.