Harold Melvin and the Blue Notes was an American soul and R&B group formed in the 1960s. The group is best known for its smooth harmonies and powerful ballads, which became popular during the Philadelphia soul music era. Their most famous hits include "If You Don't Know Me by Now" and "Wake Up Everybody," showcasing their emotional delivery and social themes. The group originally featured Teddy Pendergrass as the lead singer, who later embarked on a successful solo career. Harold Melvin, the group's namesake, played a significant role in shaping their sound and image. The Blue Notes left a lasting impact on the music industry and continue to influence artists today.