cantor and choir

[Dr. med. Kai Lautenschläger]

Hi Everyone,

typesetting liturgical music I need a solution for the following problem:

I have a solo system in change with a choir staff. solo staff should go on in 
highest choirstaff system (first tenor) when solo changes to choir. choirstaff 
(complete) should vanish completely, when choir changes to solo. 

I could find a solution in the lilypond help. Can anyone suggest an idea?

Thanks in advance!

Best regards
Kai