Brisbane

The precise starts and ends of musical periods are obviously fuzzy and any attempt to definitively say that this is where it is is inevitably going to be wrong.

That said, I still find it a fun conversation to have for its own sake. People naturally like to find ways to put things into discrete boxes. And as a rule of thumb, I've always used Monteverdi's L'Orfeo as the start of the Baroque, but I don't really have a marker for the start of the Renaissance. (For completeness, my usual marker for where Baroque music ends is the death of Bach, and the Romantic period starts with Beethoven's 3rd symphony—that last is the only one I feel particularly strongly about as more than just a convenient marker.)

But if we say 100 years, I don't agree that it's a short time. The entire common practice period lasted about 3 centuries, so a 1 century gap is pretty significant when you think about how much music evolved over that time. Obviously there are some notable similarities—particularly in timbre—between mediaeval and Baroque music. However—and maybe this is just my bias as someone whose study mostly focused on the common practice period and 20th century, and whose personal interest is mostly in the Romantic and 20th century—I think that the differences between the Baroque and mediaeval are pretty stark, with the Baroque having more in common with Classical and even Romantic eras.