war singer - do I have to choose one performance?

[Natural 1s]

Does war singer double ranges of all audible performances or do I have to choose only one?

And if only one - could I choose any time starting a performance or should I select one when taking the feat?

[Cavall]

The word chosen in the ability seems out of place as all it needs is a performance with audible abilities.

Since you can only have one on at a time that may be the reason they say chosen