The Staple Singers

The Staple Singers were an American gospel, soul, and R&B singing group. Roebuck "Pops" Staples (1914–2000), the patriarch of the family, formed the group with his children Cleotha (1934–2013), Pervis (b. 1935), Yvonne (b. 1936), and Mavis (b. 1939). They are best known for their 1970s hits "Respect Yourself", "I'll Take You There", "If You're Ready (Come Go with Me)", and "Let's Do It Again".

source: Wikipedia