Starting with a fresh Xubuntu 16.04, gdebi reports one package to remove (libjack-jackd2-0) and 196 packages to install.
So this is a fresh install of Xubuntu 16.04, with nothing else on it?
At the end, purr-data install on the unmet dependency on libjack-jackd2-0. Reinstalling ends up with a missing libstk0-dev. Here I stopped for now. The standard installer "Software Installer" does not work, and gdebi seems to have problems. There is a way to end up with a working purr-data, but it isn't a click-and-run exercise.
Well, it is a click-and-run exercise on Ubuntu 16.04. I just installed it using Ubuntu's "Software Installer" with no errors.
-Jonathan
Fred Jan