Repeating \markup commands

[David Sumbler]

The piece I am setting has a narrator.  For the score I have worked out
a way of adding the narrator's short speeches over the music which
gives the appearance I want.

It entails using the same markup commands for every individual speech,
e.g.:

s^\markup { \whiteout \pad-markup #2 "Just listen!" }

(The s is an invisible rest)

It would be nice to be able to do something like:

s^\nar "Just listen!"

How could nar be defined in this case?

David