Is there any way to put another (the same, only for practicity) time signature on the other choir?
Yes, as that’s a time signature shown at system object positions, changing the selected instrument families for system objects should include these time signatures. That will include other system objects though, such as tempo marks.
Thanks!! But (i think) that the problem is that my 2 choirs aren’t Instrument families, so If I select singers as a family, Dorico doesn’t recognize it.
Ah yes of course, sorry I missed that the top bracket are also singers - yes that option only works on the first bracket of the instrument family. You could instead change the 2nd choir instruments into e.g. strings and change their names manually?
Mmmmm, that’s an option, but the singers are [singer + bongos (1 line)] but I’ll try, thanks!