Quote within markup

[Palmer, Ralph]

Greetings -

I'm grateful for LilyPond, and for all the work a number of you are
putting into the program and the documentation. I can find answers to
most of my questions, although some take some experimentation. At this
stage, my biggest difficulty, I think, is understanding the syntax -
some commands come before notes, some are attached to the "backs" of
notes, and I'm not clear about the relationship between Scheme and
LilyPond.

My immediate problem is adding quotation marks within a markup. Nothing
I've tried works. LilyPond appears to interpret the quotation marks as a
command to keep the (my quoted) text together. My latest attempt:

e'''2 r2 ^\markup { \center-align { \line { (to aud.): "A TRIO." }}}

Any suggestions would be appreciated.

Thanks for your time and attention,

Ralph