QUOTE(anacrusis @ Apr 6 2006, 11:47 PM)
If you go a lot earlier than Vivaldi, there's lots of Italian music which has shifts in time signature - Dario Castello's sonatas prima and secunda for a treble instrument - violin, soprano recorder or cornetto, for instance. But he's 1620s-ish. There is a recording of Andrew Manze playing these on a CD called Stylus Phantasticus, I think, and the sheet music is readily available too. These are single-movement sonatas, though.
Yes of course, but I'd like to find example(s) of music written in Vivaldi's time, prefarably by the man himself.