Harmonix is looking to expand beyond their Rock Band and Dance Central franchises. This week they trademarked the term "Vidrhythm" in the United States.

"Nothing to add at this time, other than to confirm that it is a project we're working on," a Harmonix spokesperson told Joystiq.

The name Vidrhythm suggests that it'll be another rhythm game. Siliconera, who spotted the trademark registration, notes that Harmonix previously expressed interest in Nintendo 3DS, PlayStation Vita, and Facebook. It's possible that Vidrhythm might be released on one or more of those platforms.

If Harmonix is indeed preparing Vidrhythm for handhelds or social media, it'll have to be quite different from Rock Band or Dance Central. The 3DS/PSP and Facebook aren't "living room systems" like the Xbox 360 or PS3. You can't dance around like a jackass or belt out tunes while playing your 3DS on the subway. The "Vid" in the game's title suggests that the game will be more visually-oriented, which would make it more suitable for those platforms.

Vidrhythm will be the first new intellectual property created by Harmonix since the studio went independent. It essentially bought its freedom from Viacom late last year, when the publisher decided to step away from console development. The decline of the rhythm game market was also a factor.

Harmonix currently has only one officially announced project on its slate. Dance Central 2, the sequel to the Kinect launch title, was revealed at E3. It's due on the Xbox 360 later this year.