Thank you, @ccc and @cvp for the helpful replies. I reviewed the reference @cvp suggested and it clear that NavigationView isn't the best tool for what I want to do: a program that displays the chords and lyrics from ChordPro files with the correct formatting and autoscrolling, including a scrollable list of the .chordpro files and a scrollable list of songs they contain.
I was able to repurpose a single TableView to handle all of this, which saved me from the complexity of working with NavigationView. I plan to try out the script in a guitar jam next month.