Patients with intractable epilepsy treated by anterior temporal lobectomy (Right, RT, n = 12; Left, LT, n = 9) and healthy controls (n = 12) with no musical training were prospectively evaluated with a standardized battery, including the Musical Aptitude Profile and the Seashore Tonal Memory Test. Before surgery, patients performed below controls (P less than 0.001), but there were no differences between RT and LT patients. After resection (2 weeks), RT patients showed a differential decline on tasks measuring perception of meter (P = 0.005) and tempo (P = 0.008) but not tonal processes. LT, and controls studied at the same time interval, showed no decline. The results support the role of the right hemisphere in specific aspects of musical processing.