job listing specifically states the person will be responsible for creating "real-time, single-player combat experiences for a brand new IP on next-generation hardware. "
"In addition to finishing development on Rock Band Blitz and Dance Central 3, Harmonix is actively developing multiple new IPs on next generation hardware," the studio's John Drake told Kotaku. "We're looking for the best and most experienced devs out there to join us."
The studio did state in June that it was working on several new intellectual properties. Now, whether this new IP will combine music and violence like Bugsy Malone, we'll just have to wait and see.