Writing text in a measure

[Kees van den Doel]

I'm trying to write text in an otherwise empty measure (some special 
performance instructions).
not above it or below, but in it.
How can I do that? There is a snippet  doing something like that

http://lsr.dsi.unimi.it/LSR/Item?id=258

but when I apply it my text overwrites music after the bar in which the text is 
contained.

I need something like

music .. |s-\markup {"Play loud random notes, then burn your instrument (30s) 
"}| more notes...

Thanks in advance for the help,
Kees