A work can be uploaded to Petrucci Music Library US (PML-US) if it is in the public domain in the United States, but not in Canada.
To upload a work to PML-US:
If the composer whose work you are adding is "locked" (and thus does not show the menu option for adding a new work page), you may open a request for a new work page to be created. Please include in your request evidence that the work was published in 1928 or earlier or is in the public domain in the United States for another reason.