It is a very useful tool to be able to write rhythms across barlines; however, I have not been able to find a way to do this with tuplets. Since Mr. Casella apparently has figured out how (or at least make it look like it) in Green Beats 2009 (the Fumeiyo-Yori-Shi-Wo excerpt), I thought here would be a good place to ask.
That makes so much sense! Although it seems like a jerry rig type of operation, it also seems to be very easy.
Legacy Forum Post
over 14 years ago
It's in the Sibelius documentation. But the essence is that you create a time signature that is twice the counts of the one you are using (4/4 becomes 8/4). Write two bars as you would but within the time frame of that larger one. You then create a barline and do some hiding of the ";new"; time signature. The documentation is a lot more detailed than this, of course.