As August mentioned in one of his group postings concerto is really intended to be installed on a server where you have root access so you can affect changes to OS level files (services, gems, etc.) However, I was able to get it working on a hostmonster.com basic, shared hosting account by doing the following. The only drawback is that you'll need something in the cron to check and make sure the "services" are running and if not, restart them.
ssh into your account. Get the concerto code and put it under rails_apps/concerto. Add directories for log and tmp. This grabs the master branch, you might want to switch to the latest release once you git clone it.
mkdir rails_apps
cd rails_apps
git clone https://github.com/concerto/concerto
cd concerto
mkdir log
mkdir tmp