Harmonix has laid off an undisclosed number of staff today to "bring it into alignment with current product development plans".
The Rock Band developer went independent in December after breaking from former owner, MTV parent Viacom.
Speaking to Joystiq today, a Harmonix spokesperson said:
"Harmonix is restructuring our organization to bring it into alignment with our current product development plans. Unfortunately, this means reducing the number of full-time staff.
"We sincerely appreciate the work of each and every one of these employees. Harmonix is working to ensure that those affected are well taken care of as we make this change."
The company is thought to be working on an unnamed music title for Nintendo 3DS. It most recently created Dance Central for Kinect, which won positive reviews from critics.
Joystiq notes that the creation of future DLC for Rock Band 3 and Dance Central will remain unaffected by the cuts.