Pasadoble...
I work with two singers also..but not on the same job. With the 2000, you need not worry about sequeing with music. The 2000 loads registrations at lightning speed.

All you have to do is: while playing one song, open up the registration menu from the main menu (J) and scroll to the page that has the song or registration you want next. When the current song ends... open the new song and BOOM and any associated button from the 8 registration buttons...and you are ready to go.

It is the best system I have seen on any arranger.