Staff.instr

[Papazian Christophe]

Hello,

In Lilypond 2.4, I was used to set Staff.instr inside my main Voice, to
print some useful notation during a song (so each new line could have  
a different instr).
But now, I just upgraded to 2.8, and it doesn't
seem to work anymore. /set Staff.instr only seems to be useful if  
used before anything
else in a Staff. Is there some workaround ?

thank you for all the great job of lilypond dev team !

        Christophe