String Theory Entertainment CM Daniel Marrable. He's referring to the MMO-in-progress Anthymn, which is currently in the throes of a Kickstarter campaign.
Anthymn is a fantasy MMO that revolves around music for its classes, combat, and way of life. It's set in a land that's divided by musical races that are warring with each other for supremacy. A young maestro wants to create a national anthem that will not only unite his country but bring peace to the land. This quest will fuel players' adventures across the continent.
String Theory wants to create a unique feel to the title, including systems such as rhythmic gameplay, apprenticeships, and community collaboration. If the concept art looks a tad familiar, it's because a few of the devs also worked on Guild Wars 2's art.
Check out the video pitch after the jump, and drop a few bucks if you feel that Anthymn is a project worth supporting!