Sister Sledge is an American musical group from Philadelphia, Pennsylvania. Formed in 1971, the group was originally composed of sisters Debbie, Joni, Kathy and Kim Sledge. With Kathy leaving in 1989 the group have since operated as a trio (with Kathy occasionally re-joining for one-off performances and several releases in the 1990s). Having enjoyed marginal success in Europe during the middle of the decade, mainstream success was achieved when breakthrough album We Are Family was released in 1979. Symbolizing strong family values, the siblings became global superstars at the height of the disco era. The group is mostly known for the anthem, "We Are Family" and hit songs "He's the Greatest Dancer", "Lost in Music", their version of "My Guy", and "Frankie". Still performing energetic stage shows and producing music today, Sister Sledge have won in excess of 100 awards and have performed in six of the world's seven continents.