Adding a FileThere are 3 ways to attach a file to a Playlist Item:
1. Drag and drop a file from the Files app or Photos app onto a Playlist row.
2. Long press on a Playlist row and choose from the "Attach File" menu.
3. Long press on a Playlist row and choose "Edit Features", then add a file on that.

Removing a FileTo remove an attached file, long press on a Playlist row and choose "Settings". Choose "Remove" from the Attached File section.

Viewing and Editing a FileTap on the ⓘ button on the right edge of a Playlist and choose View File. To edit the file, tap the expand button in the top left - you'll then see the annotation options. Annotations can be removed later if desired.

Using the Same File for Multiple Sequential Playlist ItemsSay you're using a Playlist to program a page of music from a drum book. Each Playlist item might represent a new bar, or line of music from the page. You want to view the same page of music for each item in the Playlist. To achieve this, add a Section Header above the items and attach the file to the Section Header. This file will be displayed for all items in the section which don't have their own attached file.
Things to NoteWhen you attach a file, a copy is made in a PolyNome folder. If you move or delete the original file from your device, you won't lose the version inside PolyNome.
If you attach the same file to multiple Presets or Playlist items, a copy will be created for each attachment, resulting in multiple copies of the file. This means that if you edit the annotations of one copy, the other copies won't be updated.
To avoid this, you can utilize the same version of the file across multiple Presets by navigating to the Settings page for a Playlist item, choosing "Copy" from the Attached File section, and then selecting "Use File From Copied Preset" when attaching the file to another item. This will ensure that any annotations you make to the file will be updated across all Presets that use the same file.