"Chords" vs. "Symbols" ??

[Jeffajohnson]

This is a common UI problem: when a single command button is used as a toggle, that's considered a blooper (see the book GUI Bloopers 2.0, page 65). Users can't tell if the button label indicates the current state or the next state. No matter how which way you label it, some users will be confused. That's why it's considered a blooper. Instead of a single button, use a toggle switch, like the two-position switches in iOS and Android settings. That way no one will be confused.

[nimbleswitch]

Many thanks, Niki!! It feels natural now -- to me, at least.