The Definitive Rock Chorale was a unique musical ensemble active in the late 1960s and early 1970s. They are known for their fusion of classical music with rock, often featuring large-scale chorales accompanied by a rock band. Their distinctive sound is marked by dramatic vocal harmonies, diverse instrumentation and ambitious song structures. Although the group did not achieve broad commercial success, their innovative approach contributed to the development of progressive and symphonic rock, influencing bands such as Yes and Genesis.