Chord symbols automatically appear above rhythm section instrument staves. However, in this song it is useful to show chord symbols for other instruments too, to help their improvisation.
Prerequisite
You are in Setup mode (press Ctrl/Cmd-1).
Procedure
Result
You have set chord symbols to show in chord symbol or slash regions for the clarinet, cornet, and trombone. They were already set to show throughout the project for the banjo and piano.
Tip
You can also use this context menu to change which layouts chord symbols appear in.