Harold Melvin & the Blue Notes was an American soul and R&B group formed in the 1950s in Philadelphia. The group is best known for its smooth harmonies and powerful ballads, particularly during the 1970s. They gained fame with hits like "If You Don't Know Me by Now" and "Wake Up Everybody," showcasing their signature sound and emotional depth. The band originally featured Harold Melvin as the lead singer, but it was Teddy Pendergrass, who joined in the early 1970s, that brought them significant commercial success. Their music is often associated with the Philadelphia soul genre, characterized by lush instrumentation and heartfelt lyrics.