One Day as a Lion is a duo consisting of vocalist/keyboardist Zack de la Rocha and drummer Jon Theodore.[1] Theodore was earlier a member of The Mars Volta, while de la Rocha is a member of Rage Against the Machine. One Day as a Lion is notable for sometimes featuring de la Rocha's melodic singing rather than the rapping style he uses with Rage Against the Machine. However, de la Rocha's lyrics continue to emphasize political and activist themes.