Multiple stanzas to selection of melody

[Marten]

Dear all,

Trying to typeset a song I am faced with the following problem for which I 
can;t find a solution in the manual or snippet repository. I kindly request 
your help.

I'm typesetting a song with one staff, where the refrain comes first and 
spans multiple lines of notes; after that come 3 stanzas. I'd like the song 
text to be placed under the stanza melody, but I don't want to add empty 
lines to the refrain. I'm looking for a solution with one \score block. Can 
this be done?

In a scetch:

=====several notes, line 1 =====
Text to refrain, line 1
=====several notes, line 2 =====
Text to refrain, line 2
=====several notes, line 3 =====
Text to stanza 1, line 3
Text to stanza 2, line 3
Text to stanza 3, line 3
=====several notes, line 4 =====
Text to stanza 1, line 4
Text to stanza 2, line 4
Text to stanza 3, line 4

To me it would seem logical to change the name of the Voice in line 3, and 
the associate the lyrics of the stanzas with the voice name in line 3. But 
I don't knwo how to do this.