Sorry, I can't answer in German. In Virtual Singer, double-click on the character associated to the staff (Soprano Classic, for example). You will get a setup window where you can change the singer (to Modern, in that case)
Sorry about that. I used automatic translation and I must have missed something out. Quote:
I would like to change the voice within one System. For examble: Beginning with "Sopran Classic" and after 20 measures Change in "Sopran Modern".
I see... Click on the red/blue triangle in the icon bar (Ctrl+T if not visible) and click on the "Duplicate" option. A second staff will appear underneath the first one. Change its name to "modern" (or whatever name you like) Select both staves and do Edit>Multi-voice staves>Merge. In Virtual singer, set the singer of the second voice to "modern" and leave the first singer to "classical". Then do Options>Limit editing to one bar (must be checked) and... 1- select voice 1 (classical) with the red/blue triangle. Erase all the passages that are supposed to be sung by the "modern" soprano. 2- select voice 2 (modern). Erase all the parts that are supposed to be sung by the "classical" soprano.