Muscle-specific component of the BAF complex, a multiprotein complex involved in transcriptional activation and repression of select genes by chromatin remodeling (alteration of DNA-nucleosome topology). Specifically binds acetylated lysines on histone 3 and 4. In the complex, it acts as a tissue-specific anchor between histone acetylations and methylations and chromatin remodeling. Belongs to the neuron-specific chromatin remodeling complex (nBAF complex) and may play a role in neural development (By similarity). Plays an essential role in heart and skeletal muscle development. Component of the BAF complex. Interacts with acetylated histones H3 and H4. Component of neuron-specific chromatin remodeling complex (nBAF complex), a subfamily of ATP-dependent SWI/SNF chromatin remodeling complexes (By similarity). Expressed in the heart and somites. The PHD-type zinc fingers mediate the binding to acetylated histones.