Place arbitrary text in front of a system
I am setting some chants, each consisting of one or two systems, together onto one page. I would like to add text in centre of, and before the start of first system of each chant. This text acts in the same way as adding a instrument long name to one of the parts - it will shorten the system by the length of the text and put the text before the first bar of the stave.
It may be that there is some way of changing the instrument long name on a system by system basis. If there is, then that works because I can name just one part and move it up and down as I want. I just haven't found the method to do that (yet).