Let rho : Gal((Q) over bar /Q) -> GO(4)((Q) over bar (p)) be a continuous representation. We prove (potential) automorphy theorems for certain types of rho. Our results include several cases in which the Hodge-Tate weights are irregular. Finally, we prove (potential) automorphy for certain compatible systems of representations of GO(4)-type, which includes certain compatible systems constructed from Scholl motives. (C) 2015 Elsevier Inc. All rights reserved.